Materiały źródłowe

• #1 Spider Bites: Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/16639-spider-bites

  Most spider bites only rarely cause serious problems. […] Bites from black widow, brown recluse and hobo spiders are more serious. […] Spider bite symptoms vary depending on the type of spider. […] Spiders aren’t typically aggressive toward humans. Bites occur when spiders feel threatened and need to defend themselves. […] Black widow bites are the most serious. […] Some brown recluse bites cause a skin ulcer (wound). If the wound doesn’t heal, you might need surgery.

• #2 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  Serious symptoms include pain, itching, redness, swelling, and headaches. […] Because of its large jaws, a camel spider can leave a significant wound in human skin. […] You may also experience swelling around the bite wound and mild to intense bleeding. […] Always seek medical attention if you suspect you or someone else has symptoms of a spider bite. […] For the best outcome, seek treatment for a spider bite within 24 hours of being bitten. […] However, the bite of a few spiders such as the black widow and the tarantula can cause serious harm to humans.

• #3 Spider bites // Middlesex Health

  https://middlesexhealth.org/learning-center/diseases-and-conditions/spider-bites

  Spider bites can cause redness, pain and swelling, or you might not notice them at all. […] Worldwide only a few species of spiders have fangs long enough to penetrate human skin and venom strong enough to hurt humans. […] Severe spider bite symptoms occur as a result of the venom that the spider injects. Symptom severity depends on the type of spider, the amount of venom injected and how sensitive your body is to the venom.

• #4 How to Identify Spider Bites | Spider Bite Facts | Orkin

  https://www.orkin.com/pests/spiders/what-do-spider-bites-look-like

  Spiders are among the most numerous and diverse creatures on earth, represented by more than 30,000 species ranging in size from less than inch to 7 inches long. […] However, the occurrence of spider bites seems to attract a lot of attention and their value is quickly overshadowed by the alarm created by the thought of spider bites. […] Yet, there are very few species of spiders that cause serious medical problems to humans since most do not possess mouthparts that are strong enough or large enough to penetrate human skin and deliver their venom. […] Additionally, we may be affected by envenomization, the process of injecting venom by biting. […] In the United States, spider bites that cause significant local or systemic (affecting the entire body) reactions can be categorized into three basic groups:

• #5 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  A spider bite, also known as arachnidism, is an injury resulting from the bite of a spider. The effects of most bites are not serious. Most bites result in mild symptoms around the area of the bite. Rarely they may produce a necrotic skin wound or severe pain. Most spiders do not cause bites that are of importance. For a bite to be significant, substantial envenomation is required. Bites from the widow spiders involve a neurotoxic venom which produces a condition known as latrodectism. Symptoms may include pain which may be at the bite or involve the chest and abdomen, sweating, muscle cramps and vomiting among others. Bites from the recluse spiders cause the condition loxoscelism, in which local necrosis of the surrounding skin and widespread breakdown of red blood cells may occur. Headaches, vomiting and a mild fever may also occur. Other spiders that can cause significant bites include the Australian funnel-web spider and South American wandering spider.

• #6 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. […] A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites involve injection of venom, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider could inject when biting. While venoms are by definition toxic substances, most spiders do not have venom that is directly toxic (in the quantities delivered) to require medical attention and, of those that do, severity is typically mild. Spider venoms work on one of two fundamental principles; they are either neurotoxic (attacking the nervous system) or necrotic (attacking tissues surrounding the bite). In some cases, the venom affects vital organs and systems. The venoms of the widow spiders, Brazilian wandering spider and Australian funnel-web are neurotoxic. Heart muscle damage is an unusual complication of widow venom that may lead to death. Pulmonary edema, which is fluid accumulation in the lungs, is a feared and potentially serious but uncommon complication of funnel-web venom. Recluse and South African sand spider venoms are necrotic. Recluse venom may also cause severe hemolysis (destruction of red blood cells), though this is typically uncommon.

• #7 How to Identify Spider Bites | Spider Bite Facts | Orkin

  https://www.orkin.com/pests/spiders/what-do-spider-bites-look-like

  The most important effect of their bites is the effect on the victims central nervous system. […] Symptoms will include intense localized pain, muscle cramps and pain, increased blood pressure, profuse sweating, nausea, and sometimes a skin rash. […] Normally the bite symptoms are localized, but this spider groups bites may sometimes cause systemic reactions such as anemia, blood in the urine, fever, rash, nausea, vomiting, and even coma in very rare instances. […] All spiders with the exception of those in the family Uloboridae use their venom to paralyze or kill prey they must consume in order to survive. […] Spider publications generally report that only about 50 species of spiders are implicated in bites that are likely to cause medical implications beyond temporary localized pain and slight swelling at the site of the bite.

• #8 Spider Bites – Injuries and Poisoning – Merck Manual Consumer Version

  https://www.merckmanuals.com/home/injuries-and-poisoning/bites-and-stings/spider-bites

  Almost all spiders are venomous. However, the fangs of most species are too short or too fragile to penetrate human skin. […] Serious injuries from spider bites can include severe wounds caused by the tissue-destroying venom of brown spiders and bodywide poisoning caused by the nerve-toxic venom of widow spiders. […] Wounds suspected of being caused by the brown spider are often caused by other problems, some potentially more serious. […] Brown spider bites are treated by caring for the wound. […] Widow spider bites are treated by relieving symptoms and sometimes giving antivenom. […] Many people mistake skin infections, some potentially serious (such as methicillin-resistant Staphylococcus aureus [MRSA] infections), or other disorders for spider bites. […] Many people falsely assume that they were bitten by a spider when they really have another disorder, such as a skin infection.

• #9 Identifying Spider Bites: Symptoms & Treatment | UPMC HealthBeat

  https://share.upmc.com/2014/10/identifying-spider-bites/

  Most common spiders have fangs that are either too short or too fragile to break through human skin. Often, their venom is not poisonous enough to cause damage. […] There are two specific spiders in the United States the brown recluse and the black widow that can cause serious and even fatal illnesses. It is important to be able to identify these spider bites in order to seek proper treatment. […] The brown recluse spider is usually found in warm, dry climates. […] The initial bite is usually painless but within 8 hours you may notice: […] Brown recluse spider bite symptoms may include: […] Death is also a rare result of brown recluse spider bites and is more common with children. […] Black widow spider bites require immediate medical attention. […] Black widow spider venom is toxic and can cause damage to the nervous system. […] In rare cases, bites can result in death mostly in children, the extremely ill, and the elderly. […] Symptoms caused by a poisonous spider bite are much worse than those of a common spider bite.

• #10 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. […] A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites involve injection of venom, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider could inject when biting. While venoms are by definition toxic substances, most spiders do not have venom that is directly toxic (in the quantities delivered) to require medical attention and, of those that do, severity is typically mild. Spider venoms work on one of two fundamental principles; they are either neurotoxic (attacking the nervous system) or necrotic (attacking tissues surrounding the bite). In some cases, the venom affects vital organs and systems. The venoms of the widow spiders, Brazilian wandering spider and Australian funnel-web are neurotoxic. Heart muscle damage is an unusual complication of widow venom that may lead to death. Pulmonary edema, which is fluid accumulation in the lungs, is a feared and potentially serious but uncommon complication of funnel-web venom. Recluse and South African sand spider venoms are necrotic. Recluse venom may also cause severe hemolysis (destruction of red blood cells), though this is typically uncommon.

• #11 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. […] A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites involve injection of venom, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider could inject when biting. While venoms are by definition toxic substances, most spiders do not have venom that is directly toxic (in the quantities delivered) to require medical attention and, of those that do, severity is typically mild. Spider venoms work on one of two fundamental principles; they are either neurotoxic (attacking the nervous system) or necrotic (attacking tissues surrounding the bite). In some cases, the venom affects vital organs and systems. The venoms of the widow spiders, Brazilian wandering spider and Australian funnel-web are neurotoxic. Heart muscle damage is an unusual complication of widow venom that may lead to death. Pulmonary edema, which is fluid accumulation in the lungs, is a feared and potentially serious but uncommon complication of funnel-web venom. Recluse and South African sand spider venoms are necrotic. Recluse venom may also cause severe hemolysis (destruction of red blood cells), though this is typically uncommon.

• #12 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. […] A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites involve injection of venom, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider could inject when biting. While venoms are by definition toxic substances, most spiders do not have venom that is directly toxic (in the quantities delivered) to require medical attention and, of those that do, severity is typically mild. Spider venoms work on one of two fundamental principles; they are either neurotoxic (attacking the nervous system) or necrotic (attacking tissues surrounding the bite). In some cases, the venom affects vital organs and systems. The venoms of the widow spiders, Brazilian wandering spider and Australian funnel-web are neurotoxic. Heart muscle damage is an unusual complication of widow venom that may lead to death. Pulmonary edema, which is fluid accumulation in the lungs, is a feared and potentially serious but uncommon complication of funnel-web venom. Recluse and South African sand spider venoms are necrotic. Recluse venom may also cause severe hemolysis (destruction of red blood cells), though this is typically uncommon.

• #13 Spider bites

  https://dermnetnz.org/topics/spider-bite

  The venom produced by spider bites is generally either neurotoxic or cytotoxic. […] The signs and symptoms from a bite from a spider with neurotoxic venom differ to those produced by a spider with cytotoxic venom. […] Although many people attribute an episode of bacterial infection (especially cellulitis and necrotising fasciitis) to an unseen spider bite, they are falsely blamed. Documented spider bites have not led to skin these infections. […] One of the most important aspects in treating spider bites it to try and identify the offending spider. The venom of spider bites is quite variable hence identification of the spider can be of value in determining the management of the condition.

• #14 Spider bites and venoms – The Australian Museum

  https://australian.museum/learn/animals/spiders/spider-bites-and-venoms/

  Spider venoms are a cocktail of many chemicals. […] Some are neurotoxins, which evolved to kill or immobilise arthropods like insects by attacking their nervous systems; others are cytotoxins which help break down the tissue so the spider can ingest a liquefied meal. Unfortunately, a few of these chemicals can be seriously toxic to people. […] There are basically two types of venom that have an effect on humans: neurotoxic and cytotoxic (or necrotic) venoms. Neurotoxic venoms work directly on the nervous system. The best known example is the venom of the Black Widow/Redback spiders (Latrodectus species). Necrotic venoms cause damage to the tissues, such as blisters and lesions. […] Recent studies of confirmed spider bites suggest that, in Australia, these bites do not cause tissue necrosis. These sorts of symptoms are most likely due to other types of clinical conditions.

• #15 Spider bites and venoms – The Australian Museum

  https://australian.museum/learn/animals/spiders/spider-bites-and-venoms/

  The main effect of a neurotoxic venom is to block nerve impulses to the muscles, causing cramps and rigidity and also disrupting many of the body’s functions. […] In extreme cases, this can result in death due to respiratory or circulatory failure. […] Necrotic venoms cause skin blisters around the site of the bite, which may lead to ulcers and tissue death – necrosis.

• #16 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. […] A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites involve injection of venom, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider could inject when biting. While venoms are by definition toxic substances, most spiders do not have venom that is directly toxic (in the quantities delivered) to require medical attention and, of those that do, severity is typically mild. Spider venoms work on one of two fundamental principles; they are either neurotoxic (attacking the nervous system) or necrotic (attacking tissues surrounding the bite). In some cases, the venom affects vital organs and systems. The venoms of the widow spiders, Brazilian wandering spider and Australian funnel-web are neurotoxic. Heart muscle damage is an unusual complication of widow venom that may lead to death. Pulmonary edema, which is fluid accumulation in the lungs, is a feared and potentially serious but uncommon complication of funnel-web venom. Recluse and South African sand spider venoms are necrotic. Recluse venom may also cause severe hemolysis (destruction of red blood cells), though this is typically uncommon.

• #17 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. […] A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites involve injection of venom, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider could inject when biting. While venoms are by definition toxic substances, most spiders do not have venom that is directly toxic (in the quantities delivered) to require medical attention and, of those that do, severity is typically mild. Spider venoms work on one of two fundamental principles; they are either neurotoxic (attacking the nervous system) or necrotic (attacking tissues surrounding the bite). In some cases, the venom affects vital organs and systems. The venoms of the widow spiders, Brazilian wandering spider and Australian funnel-web are neurotoxic. Heart muscle damage is an unusual complication of widow venom that may lead to death. Pulmonary edema, which is fluid accumulation in the lungs, is a feared and potentially serious but uncommon complication of funnel-web venom. Recluse and South African sand spider venoms are necrotic. Recluse venom may also cause severe hemolysis (destruction of red blood cells), though this is typically uncommon.

• #18 Spider bites and venoms – The Australian Museum

  https://australian.museum/learn/animals/spiders/spider-bites-and-venoms/

  The main effect of a neurotoxic venom is to block nerve impulses to the muscles, causing cramps and rigidity and also disrupting many of the body’s functions. […] In extreme cases, this can result in death due to respiratory or circulatory failure. […] Necrotic venoms cause skin blisters around the site of the bite, which may lead to ulcers and tissue death – necrosis.

• #19 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. […] A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites involve injection of venom, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider could inject when biting. While venoms are by definition toxic substances, most spiders do not have venom that is directly toxic (in the quantities delivered) to require medical attention and, of those that do, severity is typically mild. Spider venoms work on one of two fundamental principles; they are either neurotoxic (attacking the nervous system) or necrotic (attacking tissues surrounding the bite). In some cases, the venom affects vital organs and systems. The venoms of the widow spiders, Brazilian wandering spider and Australian funnel-web are neurotoxic. Heart muscle damage is an unusual complication of widow venom that may lead to death. Pulmonary edema, which is fluid accumulation in the lungs, is a feared and potentially serious but uncommon complication of funnel-web venom. Recluse and South African sand spider venoms are necrotic. Recluse venom may also cause severe hemolysis (destruction of red blood cells), though this is typically uncommon.

• #20 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. […] A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites involve injection of venom, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider could inject when biting. While venoms are by definition toxic substances, most spiders do not have venom that is directly toxic (in the quantities delivered) to require medical attention and, of those that do, severity is typically mild. Spider venoms work on one of two fundamental principles; they are either neurotoxic (attacking the nervous system) or necrotic (attacking tissues surrounding the bite). In some cases, the venom affects vital organs and systems. The venoms of the widow spiders, Brazilian wandering spider and Australian funnel-web are neurotoxic. Heart muscle damage is an unusual complication of widow venom that may lead to death. Pulmonary edema, which is fluid accumulation in the lungs, is a feared and potentially serious but uncommon complication of funnel-web venom. Recluse and South African sand spider venoms are necrotic. Recluse venom may also cause severe hemolysis (destruction of red blood cells), though this is typically uncommon.

• #21 Common Spider Bites | AAFP

  https://www.aafp.org/pubs/afp/issues/2007/0315/p869.html

  There are more than 30,000 species of spiders, most of which cannot inflict serious bites to humans because of their delicate mouthparts and impotent or prey-specific venoms. However, some spiders produce toxic venoms that can cause skin lesions, systemic illnesses, and neurotoxicity. […] Although spiders cannot transmit communicable diseases, some spiders produce toxic venom that can cause skin lesions, systemic illnesses, and neurotoxicity. […] Systemic toxicity from widow spider bites (i.e., latrodectism) is caused by -latrotoxin, a neurotoxic component of Latrodectus venom that causes massive presynaptic release of most neurotransmitters, including acetylcholine, norepinephrine, dopamine, and glutamate. […] All Loxosceles spiders in the United States may cause bites characterized by necrotic arachnidism with dermonecrotic ulceration at bite sites, presumably because of autoimmune responses from cytokines and lymphocytes and cytotoxicity from venom components (mainly sphingomyelinase D). […] Hyperbaric oxygenation has been recommended to reverse the expanding dermonecrosis of loxoscelism, but it has shown mixed treatment outcomes and is not supported by controlled trials.

• #22 Spider Bites — Louisville Lectures

  http://www.louisvillelectures.org/the-ll-blog-1/spiderbites/lehto

  Patients often present to the emergency with a variety of skin findings and worries about spider bites. In the United States, the two spiders that people are often worried about are the black widow (Latrodectus mactans) and the brown recluse (Loxosceles reclusa). Fortunately, there are only about 500 bites a year in the United States and deaths are very rare. […] The venom lacks human cytotoxic agents, so there is no local tissue injury and little to no local tenderness. The venom causes the release of norepinephrine, Gamma-Aminobutyric Acid, and acetylcholine via exocytosis of synaptic vesicles. It also leads to degeneration of motor endplates which leads to denervation as well as destabilization of nerve cell membranes, which causes a massive influx of calcium into the cells resulting in hypocalcemia.

• #23 Spider Bites — Louisville Lectures

  http://www.louisvillelectures.org/the-ll-blog-1/spiderbites/lehto

  Venom contains several enzymes and biologically active substances. Phospholipases D causes most of the clinical findings of loxoscelism, including skin necrosis, platelet disorders, hemolysis, and renal failure. […] The primary treatment for acute hemolytic anemia consists of blood transfusions for patients with rapidly falling hematocrit or uncompensated anemia. Alkalinization of the urine may be required to prevent hemoglobin-induced renal failure. Antivenom is not available in the United States.

• #24 Brown Recluse Spider Toxicity – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK537045/

  In the USA, the venom of the Loxosceles reclusa is the most potent among arachnids and most likely to cause dermonecrotic arachnidism.[2] […] Brown recluse spider venom is cytotoxic and hemolytic. It has many enzymes that contribute to the clinical manifestations. Sphingomyelinase D, one of the more well-studied components, has been shown to direct toxin-mediated hemolysis and complement-mediated erythrocyte destruction. It does this by activating the complement system. […] The brown recluse spider venom is very toxic but rarely causes much damage because of the small quantity. One of the active enzymes in the venom causes significant damage to blood vessels and cell death to the tissue at the envenomation site. Also, the venom causes the patient’s body to release inflammatory cells like interleukins and cytokines to help deal with the venom, but these cells can cause harm to the patient once they are activated; this results in red blood cell destruction (hemolysis), platelet destruction (thrombocytopenia), end-organ damage (kidney injury and coma).

• #25 Spider bites // Middlesex Health

  https://middlesexhealth.org/learning-center/diseases-and-conditions/spider-bites

  Spider bites can cause redness, pain and swelling, or you might not notice them at all. […] Worldwide only a few species of spiders have fangs long enough to penetrate human skin and venom strong enough to hurt humans. […] Severe spider bite symptoms occur as a result of the venom that the spider injects. Symptom severity depends on the type of spider, the amount of venom injected and how sensitive your body is to the venom.

• #26 Spider Bites: Symptoms, Causes, and Treatment | Red Cross

  https://www.redcross.org/take-a-class/resources/learn-first-aid/spider-bites?srsltid=AfmBOoqUJYGZpG2oqKD2JP7aBnU_QWPguFWEDrarPefuDgrxUvsrOLMg

  Few spiders in the United States can cause serious illness or death. […] The bites of the black widow and brown recluse spiders can, in rare cases, kill a person. […] Signs and symptoms of spider bites depend on the amount of venom injected and the persons sensitivity to the venom. […] The only way to be certain that a spider has bitten a person is to have witnessed it. […] Bites of black widow spiders can cause an immediate sharp pinprick pain, followed by a dull pain. Bites of brown recluse spiders may be painless at first; after an hour, pain may develop, followed by a blood-filled blister. […] This is a myth. None of these measures help slow the spread of venom but are likely to cause pain and injury. Seek medical attention as quickly as possible.

• #27 How to Identify Spider Bites | Spider Bite Facts | Orkin

  https://www.orkin.com/pests/spiders/what-do-spider-bites-look-like

  The severity of the reaction to a spider bite will differ among individuals depending upon the amount of venom injected and the autoimmune responses of the person bitten. […] However, their bite is not medically important. […] All species of Loxosceles spiders have venom capable of causing necrotic skin lesions; however, like the widow spiders, they are also considered non-aggressive biters. […] Hobo spiders have been reported to have a bite that can cause tissue necrosis similar to a brown recluse bite. […] However, the hobo spider’s bite isn’t persuasively identified as the cause of necrosis. […] Yellow sac spiders can deliver painful bites. However, they rarely result in serious medical issues. […] The parson spider, like nearly all other spiders, is not regarded as medically important.

• #28

  https://myhealth.alberta.ca/Health/pages/conditions.aspx?hwid=not40563

  A few people have severe reactions to the toxin injected by the insect or spider. A toxic reaction occurs when insect or spider venom acts like a poison in the body. […] This type of reaction can occur from one bite or sting from a highly toxic insect or spider, or from multiple bites or stings from insects or spiders not normally considered poisonous. […] Symptoms of a toxic reaction vary depending on the insect or spider, the toxicity of the venom, and the amount of venom injected. […] A toxic reaction may require immediate medical care or may lead to death.

• #29 How to Identify Spider Bites | Spider Bite Facts | Orkin

  https://www.orkin.com/pests/spiders/what-do-spider-bites-look-like

  The severity of the reaction to a spider bite will differ among individuals depending upon the amount of venom injected and the autoimmune responses of the person bitten. […] However, their bite is not medically important. […] All species of Loxosceles spiders have venom capable of causing necrotic skin lesions; however, like the widow spiders, they are also considered non-aggressive biters. […] Hobo spiders have been reported to have a bite that can cause tissue necrosis similar to a brown recluse bite. […] However, the hobo spider’s bite isn’t persuasively identified as the cause of necrosis. […] Yellow sac spiders can deliver painful bites. However, they rarely result in serious medical issues. […] The parson spider, like nearly all other spiders, is not regarded as medically important.

• #30 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Contrary to popular belief, hobo spider bites probably aren’t dangerous. […] Their venom doesn’t damage cells, and they don’t seem to carry harmful bacteria. […] In the past, people thought that wolf spider bites caused large, festering wounds. […] More recent evidence has shown that isn’t the case. […] Most times, spider bites are mild and get better on their own. […] But sometimes, they can cause more serious reactions. […] Dangerous reactions are more common among children, people older than 60, and people who have medical conditions.

• #31 Spider Bites | Disease Outbreak Control Division

  https://health.hawaii.gov/docd/disease_listing/spider-bites/

  Spider bites may occur when humans come into direct contact with spiders when working in the garden, outdoors and around the home. […] Diagnosis of spider bite is based on recent history and signs and symptoms. Specific diagnosis may be difficult to confirm without identification of the spider. […] Though rare, spider bites do occur. Your risk of being bitten increases if you live in areas where there is clutter and debris or if their habitat has been disturbed.

• #32 Spider Bites | Disease Outbreak Control Division

  https://health.hawaii.gov/docd/disease_listing/spider-bites/

  Spider bites may occur when humans come into direct contact with spiders when working in the garden, outdoors and around the home. […] Diagnosis of spider bite is based on recent history and signs and symptoms. Specific diagnosis may be difficult to confirm without identification of the spider. […] Though rare, spider bites do occur. Your risk of being bitten increases if you live in areas where there is clutter and debris or if their habitat has been disturbed.

• #33 How to Identify and Treat Spider Bites

  https://www.everydayhealth.com/bug-bites/spider-bites/

  Spider bites are uncommon, and doctors often misdiagnose them. […] Spider bites are really rare, says Jonathan Day, PhD, a professor emeritus of medical entomology at the University of Florida in Gainesville. He explains that most spider bites are more likely mosquito bites that were scratched and developed into an infection. […] There are characteristic signs and symptoms when it comes to venomous spider bites. Brown recluse bites sting, and they can resemble anything from small blisters to large, rotting-flesh sores, Vetter says. Its bite causes the collapse of the capillary bed also known as skin necrosis so people who are obese and have poor support of the capillary cells may have a more massive reaction, he explains. Along with a wide variety of skin symptoms, brown recluse bites can cause symptoms common to infections. The brown recluse’s bite is poisonous and can result in coma, kidney failure, or even death. […] Black widow bites contain potentially deadly amounts of venom and tend to cause immediate pain around the bite site. […] Vetter says spiders bite people only in self-defense. […] So while spider bites do occur, they’re far less common than most people assume.

• #34 Black Widow Spider Bite Treatment

  https://my.clevelandclinic.org/health/diseases/black-widow-spider-bite

  Female black widow spiders may bite in defense, especially after they lay eggs. […] Most spider bites are accidents. If you accidentally brush up against a spider, it’s just trying to defend itself. They don’t purposely try to attack you. […] Black widow spider bites typically occur when humans come into direct contact with their webs. They only bite when threatened. […] Black widow spiders have large fangs and glands that produce very toxic venom. When bitten, the venom attacks the nerve endings in your muscles, causing symptoms such as severe, bodywide muscle pain and cramping. […] A black widow spider bite causes a sharp, pinprick-like pain. A dull numbness in the bite area may follow. Black widow spider venom interferes with chemicals in your nerve endings. This can produce severe pain, stiffness and muscle spasms throughout your body, including your belly (abdomen), shoulders, chest and back. […] Rarely, some people have long-term pain or muscle spasms after black widow spider bites.

• #35 Black Widow Spider Bite Treatment

  https://my.clevelandclinic.org/health/diseases/black-widow-spider-bite

  Female black widow spiders may bite in defense, especially after they lay eggs. […] Most spider bites are accidents. If you accidentally brush up against a spider, it’s just trying to defend itself. They don’t purposely try to attack you. […] Black widow spider bites typically occur when humans come into direct contact with their webs. They only bite when threatened. […] Black widow spiders have large fangs and glands that produce very toxic venom. When bitten, the venom attacks the nerve endings in your muscles, causing symptoms such as severe, bodywide muscle pain and cramping. […] A black widow spider bite causes a sharp, pinprick-like pain. A dull numbness in the bite area may follow. Black widow spider venom interferes with chemicals in your nerve endings. This can produce severe pain, stiffness and muscle spasms throughout your body, including your belly (abdomen), shoulders, chest and back. […] Rarely, some people have long-term pain or muscle spasms after black widow spider bites.

• #36

  https://www.prevention.com/health/g33011148/common-bug-bite-pictures/

  What they look like: If youve got two tiny puncture marks on your skin (or see a spider crawling away), you are probably dealing with a spider bite. Redness and swelling at the site of the bite are also common. Thankfully, most spiders bite only when provoked. […] Symptoms to note: Innocuous spider bites often cause mild pain (like a bee sting) and even itching. But watch out for brown recluses and black widows: The former can cause necrotic lesions, while the latter can bring on muscle spasms, tremors, and nausea. Seek medical help if you suspect a bite from either of these spiders. […] What it looks like: The brown recluse spider, or violin spider, is about 1-inch long and has a violin-shaped mark on its upper back. It is often found in warm, dry climates and prefers to stay in undisturbed areas such as basements, closets, and attics. It is not an aggressive spider, but will attack if trapped or held against the skin. When the brown recluse bites, it is often painlessthen skin reddens, turns white, develops a red bulls-eye, blisters, and becomes painful. Venom from the brown recluse spider usually causes local tissue damage.

• #37 Spider Bites | Disease Outbreak Control Division

  https://health.hawaii.gov/docd/disease_listing/spider-bites/

  There are many species of spiders known to be found throughout Hawaii. […] Very few species are known to bite or cause harm to people as they generally feed on insects and other invertebrates. […] However, two spider species of concern that are seen in Hawaii are the Southern Black Widow (Latrodectus mactans) and the Brown Widow Spider (Latrodectus geometricus). Their bites can be dangerous and would require a visit to the doctor. […] Another spider of concern that is seen on the islands is the Bold or Daring Jumping Spider (Phidippus audax), which measures only a half inch in size. It might look harmless, but its bite is painful and may produce redness, swelling and blistering. […] Symptoms associated with spider bites can vary from mild or unnoticeable to relatively severe. Very rarely, complications or even death can occur following severe bites.

• #38 Spider bites – Diagnosis & treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/spider-bites/diagnosis-treatment/drc-20352377

  Spider bites can be mistaken for other skin sores that are red, painful or swollen. […] Many skin sores attributed to spider bites turn out to have been caused by bites from other bugs, such as ants, fleas, mites, mosquitoes and biting flies. […] The process might involve determining whether anyone saw a spider bite you, having an expert identify the spider, and ruling out other possible causes of the signs and symptoms. […] Most spider bites usually heal on their own in about a week. […] A bite from a recluse spider takes longer to heal and sometimes leaves a scar. […] If the affected area is itchy, an antihistamine, such as diphenhydramine (Benadryl) or certirizine (Zyrtec), might help. […] You might need antibiotics if the bite develops into an open wound or becomes infected. […] If a black widow bite is causing severe pain or life-threatening symptoms, your doctor might recommend antivenom, which is usually given through a vein (intravenously).

• #39 Spider Bites – Injuries and Poisoning – Merck Manual Consumer Version

  https://www.merckmanuals.com/home/injuries-and-poisoning/bites-and-stings/spider-bites

  Almost all spiders are venomous. However, the fangs of most species are too short or too fragile to penetrate human skin. […] Serious injuries from spider bites can include severe wounds caused by the tissue-destroying venom of brown spiders and bodywide poisoning caused by the nerve-toxic venom of widow spiders. […] Wounds suspected of being caused by the brown spider are often caused by other problems, some potentially more serious. […] Brown spider bites are treated by caring for the wound. […] Widow spider bites are treated by relieving symptoms and sometimes giving antivenom. […] Many people mistake skin infections, some potentially serious (such as methicillin-resistant Staphylococcus aureus [MRSA] infections), or other disorders for spider bites. […] Many people falsely assume that they were bitten by a spider when they really have another disorder, such as a skin infection.

• #40 The Surprising Cause of Most 'Spider Bites’ | Live Science

  https://www.livescience.com/37974-he-surprising-cause-of-most-spider-bites.html

  Most so-called „spider bites” are not actually spider bites, according to researchers and several recent studies. Instead, „spider bites” are more likely to be bites or stings from other arthropods such as fleas, skin reactions to chemicals or infections, said Chris Buddle, an arachnologist at McGill University in Montreal. […] The vast majority of „spider bites” are caused by something else, research shows. One study Vetter cited found that of 182 Southern California patients seeking treatment for spider bites, only 3.8 percent had actual spider bites, while 85.7 percent had infections. […] And a national study found that nearly 30 percent of people with skin lesions who said they had a spider bite actually had methicillin-resistant Staphylococcus aureus (MRSA) infections. Other things that can cause symptoms that mimic spider bites include biting fleas or bedbugs, allergies, poison oak and poison ivy, besides various viral and bacterial infections, Vetter said.

• #41 The Surprising Cause of Most 'Spider Bites’ | Live Science

  https://www.livescience.com/37974-he-surprising-cause-of-most-spider-bites.html

  Most so-called „spider bites” are not actually spider bites, according to researchers and several recent studies. Instead, „spider bites” are more likely to be bites or stings from other arthropods such as fleas, skin reactions to chemicals or infections, said Chris Buddle, an arachnologist at McGill University in Montreal. […] The vast majority of „spider bites” are caused by something else, research shows. One study Vetter cited found that of 182 Southern California patients seeking treatment for spider bites, only 3.8 percent had actual spider bites, while 85.7 percent had infections. […] And a national study found that nearly 30 percent of people with skin lesions who said they had a spider bite actually had methicillin-resistant Staphylococcus aureus (MRSA) infections. Other things that can cause symptoms that mimic spider bites include biting fleas or bedbugs, allergies, poison oak and poison ivy, besides various viral and bacterial infections, Vetter said.

• #42 Spider bites – Diagnosis & treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/spider-bites/diagnosis-treatment/drc-20352377

  Spider bites can be mistaken for other skin sores that are red, painful or swollen. […] Many skin sores attributed to spider bites turn out to have been caused by bites from other bugs, such as ants, fleas, mites, mosquitoes and biting flies. […] The process might involve determining whether anyone saw a spider bite you, having an expert identify the spider, and ruling out other possible causes of the signs and symptoms. […] Most spider bites usually heal on their own in about a week. […] A bite from a recluse spider takes longer to heal and sometimes leaves a scar. […] If the affected area is itchy, an antihistamine, such as diphenhydramine (Benadryl) or certirizine (Zyrtec), might help. […] You might need antibiotics if the bite develops into an open wound or becomes infected. […] If a black widow bite is causing severe pain or life-threatening symptoms, your doctor might recommend antivenom, which is usually given through a vein (intravenously).

• #43 The Surprising Cause of Most 'Spider Bites’ | Live Science

  https://www.livescience.com/37974-he-surprising-cause-of-most-spider-bites.html

  Most so-called „spider bites” are not actually spider bites, according to researchers and several recent studies. Instead, „spider bites” are more likely to be bites or stings from other arthropods such as fleas, skin reactions to chemicals or infections, said Chris Buddle, an arachnologist at McGill University in Montreal. […] The vast majority of „spider bites” are caused by something else, research shows. One study Vetter cited found that of 182 Southern California patients seeking treatment for spider bites, only 3.8 percent had actual spider bites, while 85.7 percent had infections. […] And a national study found that nearly 30 percent of people with skin lesions who said they had a spider bite actually had methicillin-resistant Staphylococcus aureus (MRSA) infections. Other things that can cause symptoms that mimic spider bites include biting fleas or bedbugs, allergies, poison oak and poison ivy, besides various viral and bacterial infections, Vetter said.

• #44 Causes of Necrotic Wounds other than BRS Bites | Spider Research

  https://spiders.ucr.edu/causes-necrotic-wounds-other-brs-bites

  Throughout the United States, spiders get blamed as the cause of many dermatological wounds in medical diagnoses. […] In the case of necrotic wounds, „brown recluse spider bite” is a very common conclusion of medical personnel throughout North America including such ludicrously inhospitable places as Canada and Alaska where no brown recluses have ever been found. […] The medical community is overreliant on the brown recluse as the causative agent of these wounds in many portions of the United States. […] General practitioners often go to the „brown recluse bite” diagnosis as a causative agent when they have little proof that a spider is involved. […] The diagnosis of brown recluse spider bite is overused for dermonecrotic wounds of uncertain etiology.

• #45 Causes of Necrotic Wounds other than BRS Bites | Spider Research

  https://spiders.ucr.edu/causes-necrotic-wounds-other-brs-bites

  Throughout the United States, spiders get blamed as the cause of many dermatological wounds in medical diagnoses. […] In the case of necrotic wounds, „brown recluse spider bite” is a very common conclusion of medical personnel throughout North America including such ludicrously inhospitable places as Canada and Alaska where no brown recluses have ever been found. […] The medical community is overreliant on the brown recluse as the causative agent of these wounds in many portions of the United States. […] General practitioners often go to the „brown recluse bite” diagnosis as a causative agent when they have little proof that a spider is involved. […] The diagnosis of brown recluse spider bite is overused for dermonecrotic wounds of uncertain etiology.

• #46 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Spiders live all over the United States. […] Spider bites are fairly uncommon. […] If a spider does bite you, it usually isn’t a problem. […] The CDC says only two venomous spiders that are native to the United States can do real harm when they bite a person: black widows and brown recluses. […] Black widow spiders live throughout the United States but are most common in the South and West. […] Only female black widows have neurotoxic venom. […] Brown recluse spiders live in the Midwest and South. […] Brown recluse venom can severely damage skin, causing a necrotic wound (a wound in which tissue dies). […] For years, people mistakenly believed that hobo spiders caused dangerous wounds. […] In reality, about 10% of brown recluse spider bites cause severe skin damage. […] Brown recluse spiders have a bad reputation for causing large, festering wounds.

• #47 Spider Bites

  https://healthlibrary.uwmedicine.org/Library/DiseasesConditions/Adult/Pathology/85,P00860

  Most spiders found in the U.S. are harmless, except for the brown recluse and the black widow spiders. […] Venom from the brown recluse spider often causes local skin tissue damage. […] Black widow spider bites release a poison that can damage the nervous system. Emergency care is needed right away. […] Symptoms of a brown recluse spider bite include a deep blue or purple area around the bite, surrounded by a whitish ring and large red outer ring like a target or bulls-eye. […] Symptoms of a black widow spider bite include cramping pain and muscle stiffness. There may also be weakness, tremors, or paralysis, especially in the legs.

• #48 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Contrary to popular belief, hobo spider bites probably aren’t dangerous. […] Their venom doesn’t damage cells, and they don’t seem to carry harmful bacteria. […] In the past, people thought that wolf spider bites caused large, festering wounds. […] More recent evidence has shown that isn’t the case. […] Most times, spider bites are mild and get better on their own. […] But sometimes, they can cause more serious reactions. […] Dangerous reactions are more common among children, people older than 60, and people who have medical conditions.

• #49 Spider Bites | Disease Outbreak Control Division

  https://health.hawaii.gov/docd/disease_listing/spider-bites/

  There are many species of spiders known to be found throughout Hawaii. […] Very few species are known to bite or cause harm to people as they generally feed on insects and other invertebrates. […] However, two spider species of concern that are seen in Hawaii are the Southern Black Widow (Latrodectus mactans) and the Brown Widow Spider (Latrodectus geometricus). Their bites can be dangerous and would require a visit to the doctor. […] Another spider of concern that is seen on the islands is the Bold or Daring Jumping Spider (Phidippus audax), which measures only a half inch in size. It might look harmless, but its bite is painful and may produce redness, swelling and blistering. […] Symptoms associated with spider bites can vary from mild or unnoticeable to relatively severe. Very rarely, complications or even death can occur following severe bites.

• #50 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  After 1 hour, the site will start to turn red. In 8 hours, itll become hardened and swollen. After 24 to 26 hours, the wound may discharge fluids and eventually turn black. […] Hobo spider bites are slow to heal. Seek immediate medical treatment if you suspect a hobo spider has bitten you. […] The bite of a Brazilian wandering spider is extremely painful. It can quickly result in heavy sweating and drooling. The skin around the bite will usually swell, turn red, and get hot. […] In severe cases, the bite can result in dead tissue or death. […] A wolf spiders bite may tear the skin and cause pain, redness, and swelling. […] For some people, healing can take up to 10 days. In rare cases, the bite can lead to tissue damage. […] The jumping spiders bite is usually no worse than a wasp sting. It can be dangerous if youre allergic to spider venom.

• #51 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. […] A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites involve injection of venom, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider could inject when biting. While venoms are by definition toxic substances, most spiders do not have venom that is directly toxic (in the quantities delivered) to require medical attention and, of those that do, severity is typically mild. Spider venoms work on one of two fundamental principles; they are either neurotoxic (attacking the nervous system) or necrotic (attacking tissues surrounding the bite). In some cases, the venom affects vital organs and systems. The venoms of the widow spiders, Brazilian wandering spider and Australian funnel-web are neurotoxic. Heart muscle damage is an unusual complication of widow venom that may lead to death. Pulmonary edema, which is fluid accumulation in the lungs, is a feared and potentially serious but uncommon complication of funnel-web venom. Recluse and South African sand spider venoms are necrotic. Recluse venom may also cause severe hemolysis (destruction of red blood cells), though this is typically uncommon.

• #52 Spider Bites | Disease Outbreak Control Division

  https://health.hawaii.gov/docd/disease_listing/spider-bites/

  There are many species of spiders known to be found throughout Hawaii. […] Very few species are known to bite or cause harm to people as they generally feed on insects and other invertebrates. […] However, two spider species of concern that are seen in Hawaii are the Southern Black Widow (Latrodectus mactans) and the Brown Widow Spider (Latrodectus geometricus). Their bites can be dangerous and would require a visit to the doctor. […] Another spider of concern that is seen on the islands is the Bold or Daring Jumping Spider (Phidippus audax), which measures only a half inch in size. It might look harmless, but its bite is painful and may produce redness, swelling and blistering. […] Symptoms associated with spider bites can vary from mild or unnoticeable to relatively severe. Very rarely, complications or even death can occur following severe bites.

• #53 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  A spider bite, also known as arachnidism, is an injury resulting from the bite of a spider. The effects of most bites are not serious. Most bites result in mild symptoms around the area of the bite. Rarely they may produce a necrotic skin wound or severe pain. Most spiders do not cause bites that are of importance. For a bite to be significant, substantial envenomation is required. Bites from the widow spiders involve a neurotoxic venom which produces a condition known as latrodectism. Symptoms may include pain which may be at the bite or involve the chest and abdomen, sweating, muscle cramps and vomiting among others. Bites from the recluse spiders cause the condition loxoscelism, in which local necrosis of the surrounding skin and widespread breakdown of red blood cells may occur. Headaches, vomiting and a mild fever may also occur. Other spiders that can cause significant bites include the Australian funnel-web spider and South American wandering spider.

• #54 Spider bites – Diagnosis & treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/spider-bites/diagnosis-treatment/drc-20352377

  Spider bites can be mistaken for other skin sores that are red, painful or swollen. […] Many skin sores attributed to spider bites turn out to have been caused by bites from other bugs, such as ants, fleas, mites, mosquitoes and biting flies. […] The process might involve determining whether anyone saw a spider bite you, having an expert identify the spider, and ruling out other possible causes of the signs and symptoms. […] Most spider bites usually heal on their own in about a week. […] A bite from a recluse spider takes longer to heal and sometimes leaves a scar. […] If the affected area is itchy, an antihistamine, such as diphenhydramine (Benadryl) or certirizine (Zyrtec), might help. […] You might need antibiotics if the bite develops into an open wound or becomes infected. […] If a black widow bite is causing severe pain or life-threatening symptoms, your doctor might recommend antivenom, which is usually given through a vein (intravenously).

• #55 Spider bite – PubMed

  https://pubmed.ncbi.nlm.nih.gov/21762981/

  Spiders are a source of intrigue and fear, and several myths exist about their medical effects. […] Many people believe that bites from various spider species cause necrotic ulceration, despite evidence that most suspected cases of necrotic arachnidism are caused by something other than a spider bite. Latrodectism and loxoscelism are the most important clinical syndromes resulting from spider bite. Latrodectism results from bites by widow spiders (Latrodectus spp) and causes local, regional, or generalised pain associated with non-specific symptoms and autonomic effects. Loxoscelism is caused by Loxosceles spp, and the cutaneous form manifests as pain and erythema that can develop into a necrotic ulcer. Systemic loxoscelism is characterised by intravascular haemolysis and renal failure on occasion. […] Other important spiders include the Australian funnel-web spider (Atrax spp and Hadronyche spp) and the armed spider (Phoneutria spp) from Brazil.

• #56 Spider bite – PubMed

  https://pubmed.ncbi.nlm.nih.gov/21762981/

  Spiders are a source of intrigue and fear, and several myths exist about their medical effects. […] Many people believe that bites from various spider species cause necrotic ulceration, despite evidence that most suspected cases of necrotic arachnidism are caused by something other than a spider bite. Latrodectism and loxoscelism are the most important clinical syndromes resulting from spider bite. Latrodectism results from bites by widow spiders (Latrodectus spp) and causes local, regional, or generalised pain associated with non-specific symptoms and autonomic effects. Loxoscelism is caused by Loxosceles spp, and the cutaneous form manifests as pain and erythema that can develop into a necrotic ulcer. Systemic loxoscelism is characterised by intravascular haemolysis and renal failure on occasion. […] Other important spiders include the Australian funnel-web spider (Atrax spp and Hadronyche spp) and the armed spider (Phoneutria spp) from Brazil.

• #57 Spider bite – PubMed

  https://pubmed.ncbi.nlm.nih.gov/21762981/

  Spiders are a source of intrigue and fear, and several myths exist about their medical effects. […] Many people believe that bites from various spider species cause necrotic ulceration, despite evidence that most suspected cases of necrotic arachnidism are caused by something other than a spider bite. Latrodectism and loxoscelism are the most important clinical syndromes resulting from spider bite. Latrodectism results from bites by widow spiders (Latrodectus spp) and causes local, regional, or generalised pain associated with non-specific symptoms and autonomic effects. Loxoscelism is caused by Loxosceles spp, and the cutaneous form manifests as pain and erythema that can develop into a necrotic ulcer. Systemic loxoscelism is characterised by intravascular haemolysis and renal failure on occasion. […] Other important spiders include the Australian funnel-web spider (Atrax spp and Hadronyche spp) and the armed spider (Phoneutria spp) from Brazil.

• #58 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Spiders live all over the United States. […] Spider bites are fairly uncommon. […] If a spider does bite you, it usually isn’t a problem. […] The CDC says only two venomous spiders that are native to the United States can do real harm when they bite a person: black widows and brown recluses. […] Black widow spiders live throughout the United States but are most common in the South and West. […] Only female black widows have neurotoxic venom. […] Brown recluse spiders live in the Midwest and South. […] Brown recluse venom can severely damage skin, causing a necrotic wound (a wound in which tissue dies). […] For years, people mistakenly believed that hobo spiders caused dangerous wounds. […] In reality, about 10% of brown recluse spider bites cause severe skin damage. […] Brown recluse spiders have a bad reputation for causing large, festering wounds.

• #59 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Spiders live all over the United States. […] Spider bites are fairly uncommon. […] If a spider does bite you, it usually isn’t a problem. […] The CDC says only two venomous spiders that are native to the United States can do real harm when they bite a person: black widows and brown recluses. […] Black widow spiders live throughout the United States but are most common in the South and West. […] Only female black widows have neurotoxic venom. […] Brown recluse spiders live in the Midwest and South. […] Brown recluse venom can severely damage skin, causing a necrotic wound (a wound in which tissue dies). […] For years, people mistakenly believed that hobo spiders caused dangerous wounds. […] In reality, about 10% of brown recluse spider bites cause severe skin damage. […] Brown recluse spiders have a bad reputation for causing large, festering wounds.

• #60 Spider Bites | VCA Canada Animal Hospitals

  https://vcahospitals.com/know-your-pet/spider-bites

  Female black widows are significantly larger and more venomous than males. […] The effects of black widow and brown recluse spider bites vary significantly due to differences in the venom of these two types of spiders. […] Black widow spider venom contains a neurotoxin. This substance causes massive excitation of neurons (the cells within the nervous system), leading to muscle tremors and other effects seen in black widow envenomation. […] Brown recluse spider venom, in contrast, contains several substances that trigger local tissue effects. The first part of brown recluse venom contains a substance known as sphingomyelinase D, which interferes with blood clotting at the site of the bite. Additional toxins are injected into the bite victim, contributing to local inflammation and tissue necrosis. […] The only way to definitively diagnose a spider bite is to collect and identify the spider responsible for causing the bite.

• #61 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  The bite can blister and grow progressively worse without treatment to the point where it may kill surrounding tissue and cause fever, chills, and headache. […] On rare occasions, it can cause coma or seizures, jaundice, blood in urine, and kidney failure. […] The black widow spider is of the Latrodectus (widow) family of spiders. […] Only the female black widow is toxic. Black widow bites can feel like a small pinprick or nothing at all, but your skins reaction will be immediate. […] Within an hour, you may start to notice muscle cramping, pain and burning at the puncture site, headache, high blood pressure, increased saliva and sweating, nausea and vomiting, numbness, and restlessness. […] Hobo spiders can bite when provoked. […] You may not notice a bite from a hobo spider at first, but itll cause pain and numbness within 15 minutes.

• #62 Spider Bites: Symptoms, Causes, and Treatment | Red Cross

  https://www.redcross.org/take-a-class/resources/learn-first-aid/spider-bites?srsltid=AfmBOoqUJYGZpG2oqKD2JP7aBnU_QWPguFWEDrarPefuDgrxUvsrOLMg

  Few spiders in the United States can cause serious illness or death. […] The bites of the black widow and brown recluse spiders can, in rare cases, kill a person. […] Signs and symptoms of spider bites depend on the amount of venom injected and the persons sensitivity to the venom. […] The only way to be certain that a spider has bitten a person is to have witnessed it. […] Bites of black widow spiders can cause an immediate sharp pinprick pain, followed by a dull pain. Bites of brown recluse spiders may be painless at first; after an hour, pain may develop, followed by a blood-filled blister. […] This is a myth. None of these measures help slow the spread of venom but are likely to cause pain and injury. Seek medical attention as quickly as possible.

• #63

  https://www.prevention.com/health/g33011148/common-bug-bite-pictures/

  Symptoms to note: Moderate to severe pain and itching at the site of the bite is typical and usually occurs 2 to 8 hours after the spider has injected its venom. Rare complications include fever, body aches, nausea, vomiting, hemolytic anemia, rhabdomyolysis, and kidney failure. These bites can be deadly in rare cases. If you suspect that youve been bitten by a brown recluse, seek medical care immediately. If you can, bring the spider with you for positive identification. […] What it looks like: Despite the scary name, Black Widows are nonaggressive and will only bite if they are being crushed. This spider is plump, black, and shiny, with an hourglass-shaped red mark on its abdomen. The bite area will typically appear red with a white center. […] Symptoms to note: Black Widow bites cause muscle pain and spasms in the arms, legs, abdomen, and back. Tremor, sweating, weakness, chills, nausea, vomiting, and headache are other symptoms. The bite area is red with a white center.

• #64 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  The bite can blister and grow progressively worse without treatment to the point where it may kill surrounding tissue and cause fever, chills, and headache. […] On rare occasions, it can cause coma or seizures, jaundice, blood in urine, and kidney failure. […] The black widow spider is of the Latrodectus (widow) family of spiders. […] Only the female black widow is toxic. Black widow bites can feel like a small pinprick or nothing at all, but your skins reaction will be immediate. […] Within an hour, you may start to notice muscle cramping, pain and burning at the puncture site, headache, high blood pressure, increased saliva and sweating, nausea and vomiting, numbness, and restlessness. […] Hobo spiders can bite when provoked. […] You may not notice a bite from a hobo spider at first, but itll cause pain and numbness within 15 minutes.

• #65 Spider Bites

  https://healthlibrary.uwmedicine.org/Library/DiseasesConditions/Adult/Pathology/85,P00860

  Most spiders found in the U.S. are harmless, except for the brown recluse and the black widow spiders. […] Venom from the brown recluse spider often causes local skin tissue damage. […] Black widow spider bites release a poison that can damage the nervous system. Emergency care is needed right away. […] Symptoms of a brown recluse spider bite include a deep blue or purple area around the bite, surrounded by a whitish ring and large red outer ring like a target or bulls-eye. […] Symptoms of a black widow spider bite include cramping pain and muscle stiffness. There may also be weakness, tremors, or paralysis, especially in the legs.

• #66 Spider Bites

  https://healthlibrary.uwmedicine.org/Library/DiseasesConditions/Adult/Pathology/85,P00860

  Most spiders found in the U.S. are harmless, except for the brown recluse and the black widow spiders. […] Venom from the brown recluse spider often causes local skin tissue damage. […] Black widow spider bites release a poison that can damage the nervous system. Emergency care is needed right away. […] Symptoms of a brown recluse spider bite include a deep blue or purple area around the bite, surrounded by a whitish ring and large red outer ring like a target or bulls-eye. […] Symptoms of a black widow spider bite include cramping pain and muscle stiffness. There may also be weakness, tremors, or paralysis, especially in the legs.

• #67 Spider bites: Identification and treatment

  https://www.medicalnewstoday.com/articles/311615

  The most severe effects of a brown recluse spider bite will not occur immediately. However, the sooner a person seeks help, the lower the risk that tissue damage will occur. […] The black widow spider has a reputation for giving a deadly bite. While the bite can be dangerous, especially for young people and older adults, it is not usually life threatening. […] In some cases, the pain may be severe, resembling that of appendicitis or a heart attack. […] Anyone who has concerns about a bite or other skin symptoms should contact a doctor for diagnosis.

• #68 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Spiders live all over the United States. […] Spider bites are fairly uncommon. […] If a spider does bite you, it usually isn’t a problem. […] The CDC says only two venomous spiders that are native to the United States can do real harm when they bite a person: black widows and brown recluses. […] Black widow spiders live throughout the United States but are most common in the South and West. […] Only female black widows have neurotoxic venom. […] Brown recluse spiders live in the Midwest and South. […] Brown recluse venom can severely damage skin, causing a necrotic wound (a wound in which tissue dies). […] For years, people mistakenly believed that hobo spiders caused dangerous wounds. […] In reality, about 10% of brown recluse spider bites cause severe skin damage. […] Brown recluse spiders have a bad reputation for causing large, festering wounds.

• #69 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Spiders live all over the United States. […] Spider bites are fairly uncommon. […] If a spider does bite you, it usually isn’t a problem. […] The CDC says only two venomous spiders that are native to the United States can do real harm when they bite a person: black widows and brown recluses. […] Black widow spiders live throughout the United States but are most common in the South and West. […] Only female black widows have neurotoxic venom. […] Brown recluse spiders live in the Midwest and South. […] Brown recluse venom can severely damage skin, causing a necrotic wound (a wound in which tissue dies). […] For years, people mistakenly believed that hobo spiders caused dangerous wounds. […] In reality, about 10% of brown recluse spider bites cause severe skin damage. […] Brown recluse spiders have a bad reputation for causing large, festering wounds.

• #70 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  When a spider bites, it may leave two marks on the skin. Some spider bites can produce severe symptoms, but very few are life threatening, and most spiders cannot bite humans. […] Most spiders bite, but their fangs are too small or weak to puncture human skin. Many spiders have weak or prey-specific toxins that are unlikely to affect humans. If they do bite, they may leave itchy, red wounds that heal within a week or so. […] However, some spiders can bite through human skin and insert powerful toxins. Bites by these spiders are rarely fatal but can cause health complications, such as tissue death and painful muscle spasms. […] The initial brown recluse bite may be painless, but within 28 hours, itll begin to itch, hurt, and turn red. A red or purple ring resembling a target or bulls-eye will develop around the bite.

• #71 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  When a spider bites, it may leave two marks on the skin. Some spider bites can produce severe symptoms, but very few are life threatening, and most spiders cannot bite humans. […] Most spiders bite, but their fangs are too small or weak to puncture human skin. Many spiders have weak or prey-specific toxins that are unlikely to affect humans. If they do bite, they may leave itchy, red wounds that heal within a week or so. […] However, some spiders can bite through human skin and insert powerful toxins. Bites by these spiders are rarely fatal but can cause health complications, such as tissue death and painful muscle spasms. […] The initial brown recluse bite may be painless, but within 28 hours, itll begin to itch, hurt, and turn red. A red or purple ring resembling a target or bulls-eye will develop around the bite.

• #72 Spider Bites

  https://healthlibrary.uwmedicine.org/Library/DiseasesConditions/Adult/Pathology/85,P00860

  Most spiders found in the U.S. are harmless, except for the brown recluse and the black widow spiders. […] Venom from the brown recluse spider often causes local skin tissue damage. […] Black widow spider bites release a poison that can damage the nervous system. Emergency care is needed right away. […] Symptoms of a brown recluse spider bite include a deep blue or purple area around the bite, surrounded by a whitish ring and large red outer ring like a target or bulls-eye. […] Symptoms of a black widow spider bite include cramping pain and muscle stiffness. There may also be weakness, tremors, or paralysis, especially in the legs.

• #73 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  The bite can blister and grow progressively worse without treatment to the point where it may kill surrounding tissue and cause fever, chills, and headache. […] On rare occasions, it can cause coma or seizures, jaundice, blood in urine, and kidney failure. […] The black widow spider is of the Latrodectus (widow) family of spiders. […] Only the female black widow is toxic. Black widow bites can feel like a small pinprick or nothing at all, but your skins reaction will be immediate. […] Within an hour, you may start to notice muscle cramping, pain and burning at the puncture site, headache, high blood pressure, increased saliva and sweating, nausea and vomiting, numbness, and restlessness. […] Hobo spiders can bite when provoked. […] You may not notice a bite from a hobo spider at first, but itll cause pain and numbness within 15 minutes.

• #74 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  The bite can blister and grow progressively worse without treatment to the point where it may kill surrounding tissue and cause fever, chills, and headache. […] On rare occasions, it can cause coma or seizures, jaundice, blood in urine, and kidney failure. […] The black widow spider is of the Latrodectus (widow) family of spiders. […] Only the female black widow is toxic. Black widow bites can feel like a small pinprick or nothing at all, but your skins reaction will be immediate. […] Within an hour, you may start to notice muscle cramping, pain and burning at the puncture site, headache, high blood pressure, increased saliva and sweating, nausea and vomiting, numbness, and restlessness. […] Hobo spiders can bite when provoked. […] You may not notice a bite from a hobo spider at first, but itll cause pain and numbness within 15 minutes.

• #75 Spider bites – Diagnosis & treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/spider-bites/diagnosis-treatment/drc-20352377

  Spider bites can be mistaken for other skin sores that are red, painful or swollen. […] Many skin sores attributed to spider bites turn out to have been caused by bites from other bugs, such as ants, fleas, mites, mosquitoes and biting flies. […] The process might involve determining whether anyone saw a spider bite you, having an expert identify the spider, and ruling out other possible causes of the signs and symptoms. […] Most spider bites usually heal on their own in about a week. […] A bite from a recluse spider takes longer to heal and sometimes leaves a scar. […] If the affected area is itchy, an antihistamine, such as diphenhydramine (Benadryl) or certirizine (Zyrtec), might help. […] You might need antibiotics if the bite develops into an open wound or becomes infected. […] If a black widow bite is causing severe pain or life-threatening symptoms, your doctor might recommend antivenom, which is usually given through a vein (intravenously).

• #76 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  In most cases, the medical consequences of a spider bite are minor. Typically, the bite causes limited local tissue inflammation similar to the bites and stings of other small arthropods, and patients respond well to over-the-counter analgesics and antihistamines, if any treatment is needed. […] The bites of only a few spider species produce medically significant effects in humans. […] Clinical features. Patients who have been bitten by a brown recluse spider may report a pinprick sensation, although the bite may be painless. […] The local inflammation and tissue necrosis associated with brown recluse spider bites results from the spider’s venom, which contains enzymes and other products. […] Systemic signs and symptoms-such as arthralgia, rash, fever, vomiting, and hemolysis-are rare (between 0.7% and 1.8% of reported bites).

• #77 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Contrary to popular belief, hobo spider bites probably aren’t dangerous. […] Their venom doesn’t damage cells, and they don’t seem to carry harmful bacteria. […] In the past, people thought that wolf spider bites caused large, festering wounds. […] More recent evidence has shown that isn’t the case. […] Most times, spider bites are mild and get better on their own. […] But sometimes, they can cause more serious reactions. […] Dangerous reactions are more common among children, people older than 60, and people who have medical conditions.

• #78 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Contrary to popular belief, hobo spider bites probably aren’t dangerous. […] Their venom doesn’t damage cells, and they don’t seem to carry harmful bacteria. […] In the past, people thought that wolf spider bites caused large, festering wounds. […] More recent evidence has shown that isn’t the case. […] Most times, spider bites are mild and get better on their own. […] But sometimes, they can cause more serious reactions. […] Dangerous reactions are more common among children, people older than 60, and people who have medical conditions.

• #79 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  The bite can blister and grow progressively worse without treatment to the point where it may kill surrounding tissue and cause fever, chills, and headache. […] On rare occasions, it can cause coma or seizures, jaundice, blood in urine, and kidney failure. […] The black widow spider is of the Latrodectus (widow) family of spiders. […] Only the female black widow is toxic. Black widow bites can feel like a small pinprick or nothing at all, but your skins reaction will be immediate. […] Within an hour, you may start to notice muscle cramping, pain and burning at the puncture site, headache, high blood pressure, increased saliva and sweating, nausea and vomiting, numbness, and restlessness. […] Hobo spiders can bite when provoked. […] You may not notice a bite from a hobo spider at first, but itll cause pain and numbness within 15 minutes.

• #80 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  After 1 hour, the site will start to turn red. In 8 hours, itll become hardened and swollen. After 24 to 26 hours, the wound may discharge fluids and eventually turn black. […] Hobo spider bites are slow to heal. Seek immediate medical treatment if you suspect a hobo spider has bitten you. […] The bite of a Brazilian wandering spider is extremely painful. It can quickly result in heavy sweating and drooling. The skin around the bite will usually swell, turn red, and get hot. […] In severe cases, the bite can result in dead tissue or death. […] A wolf spiders bite may tear the skin and cause pain, redness, and swelling. […] For some people, healing can take up to 10 days. In rare cases, the bite can lead to tissue damage. […] The jumping spiders bite is usually no worse than a wasp sting. It can be dangerous if youre allergic to spider venom.

• #81 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  After 1 hour, the site will start to turn red. In 8 hours, itll become hardened and swollen. After 24 to 26 hours, the wound may discharge fluids and eventually turn black. […] Hobo spider bites are slow to heal. Seek immediate medical treatment if you suspect a hobo spider has bitten you. […] The bite of a Brazilian wandering spider is extremely painful. It can quickly result in heavy sweating and drooling. The skin around the bite will usually swell, turn red, and get hot. […] In severe cases, the bite can result in dead tissue or death. […] A wolf spiders bite may tear the skin and cause pain, redness, and swelling. […] For some people, healing can take up to 10 days. In rare cases, the bite can lead to tissue damage. […] The jumping spiders bite is usually no worse than a wasp sting. It can be dangerous if youre allergic to spider venom.

• #82 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  After 1 hour, the site will start to turn red. In 8 hours, itll become hardened and swollen. After 24 to 26 hours, the wound may discharge fluids and eventually turn black. […] Hobo spider bites are slow to heal. Seek immediate medical treatment if you suspect a hobo spider has bitten you. […] The bite of a Brazilian wandering spider is extremely painful. It can quickly result in heavy sweating and drooling. The skin around the bite will usually swell, turn red, and get hot. […] In severe cases, the bite can result in dead tissue or death. […] A wolf spiders bite may tear the skin and cause pain, redness, and swelling. […] For some people, healing can take up to 10 days. In rare cases, the bite can lead to tissue damage. […] The jumping spiders bite is usually no worse than a wasp sting. It can be dangerous if youre allergic to spider venom.

• #83 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  After 1 hour, the site will start to turn red. In 8 hours, itll become hardened and swollen. After 24 to 26 hours, the wound may discharge fluids and eventually turn black. […] Hobo spider bites are slow to heal. Seek immediate medical treatment if you suspect a hobo spider has bitten you. […] The bite of a Brazilian wandering spider is extremely painful. It can quickly result in heavy sweating and drooling. The skin around the bite will usually swell, turn red, and get hot. […] In severe cases, the bite can result in dead tissue or death. […] A wolf spiders bite may tear the skin and cause pain, redness, and swelling. […] For some people, healing can take up to 10 days. In rare cases, the bite can lead to tissue damage. […] The jumping spiders bite is usually no worse than a wasp sting. It can be dangerous if youre allergic to spider venom.

• #84 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  Serious symptoms include pain, itching, redness, swelling, and headaches. […] Because of its large jaws, a camel spider can leave a significant wound in human skin. […] You may also experience swelling around the bite wound and mild to intense bleeding. […] Always seek medical attention if you suspect you or someone else has symptoms of a spider bite. […] For the best outcome, seek treatment for a spider bite within 24 hours of being bitten. […] However, the bite of a few spiders such as the black widow and the tarantula can cause serious harm to humans.

• #85 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  Serious symptoms include pain, itching, redness, swelling, and headaches. […] Because of its large jaws, a camel spider can leave a significant wound in human skin. […] You may also experience swelling around the bite wound and mild to intense bleeding. […] Always seek medical attention if you suspect you or someone else has symptoms of a spider bite. […] For the best outcome, seek treatment for a spider bite within 24 hours of being bitten. […] However, the bite of a few spiders such as the black widow and the tarantula can cause serious harm to humans.

• #86 Spider Bites: Identify What Bit You and Get Proper Help

  https://www.healthline.com/health/spider-bites

  Serious symptoms include pain, itching, redness, swelling, and headaches. […] Because of its large jaws, a camel spider can leave a significant wound in human skin. […] You may also experience swelling around the bite wound and mild to intense bleeding. […] Always seek medical attention if you suspect you or someone else has symptoms of a spider bite. […] For the best outcome, seek treatment for a spider bite within 24 hours of being bitten. […] However, the bite of a few spiders such as the black widow and the tarantula can cause serious harm to humans.

• #87 Spider Bites – Causes, Symptoms, Treatment, Diagnosis – MedBroadcast.com

  https://medbroadcast.com/condition/getcondition/spider-bites

  Most spiders don’t bite humans and only do so if they’re provoked. […] However, there are a few venomous spiders in North America that can be dangerous. […] Many spiders bite, but very few are a risk to humans. […] The venom of black widow spiders is a neurotoxin (poisonous to the nervous system). […] The venom of brown recluse spiders causes necrosis (damage and breakdown) of skin and tissue. […] Tarantulas have hairs on their body and hind legs that can pierce human skin and inject a toxin. […] Most spider bites cause minor swelling, inflammation, and itching. However, bites from venomous spiders can cause more severe reactions. […] Black widow bites affect the nervous system. […] Brown recluse spider bites affect the skin and surrounding tissue. […] Tarantula hairs contain a toxin that can cause a serious skin rash, an allergic reaction, and possibly even anaphylactic shock. […] Treatment for spider bites varies according to the type of spider. […] To prevent spider bites, be careful when working outside around woodpiles or in dark places in barns and garages, and use gloves for protection.

• #88 Spider Bites – Causes, Symptoms, Treatment, Diagnosis – MedBroadcast.com

  https://medbroadcast.com/condition/getcondition/spider-bites

  Most spiders don’t bite humans and only do so if they’re provoked. […] However, there are a few venomous spiders in North America that can be dangerous. […] Many spiders bite, but very few are a risk to humans. […] The venom of black widow spiders is a neurotoxin (poisonous to the nervous system). […] The venom of brown recluse spiders causes necrosis (damage and breakdown) of skin and tissue. […] Tarantulas have hairs on their body and hind legs that can pierce human skin and inject a toxin. […] Most spider bites cause minor swelling, inflammation, and itching. However, bites from venomous spiders can cause more severe reactions. […] Black widow bites affect the nervous system. […] Brown recluse spider bites affect the skin and surrounding tissue. […] Tarantula hairs contain a toxin that can cause a serious skin rash, an allergic reaction, and possibly even anaphylactic shock. […] Treatment for spider bites varies according to the type of spider. […] To prevent spider bites, be careful when working outside around woodpiles or in dark places in barns and garages, and use gloves for protection.

• #89 Spider Bites, Bug Bites, or MRSA: Causes of Blisters

  https://www.verywellhealth.com/spider-bite-or-skin-infection-83017

  Spider bites and other insect bites can cause pus blisters, but so can a potentially serious infection known as methicillin-resistant Staphylococcus aureus (MRSA). […] Spider bite symptoms can vary from person to person as well as by species. Typically, spider bites result in fluid-filled blisters (bullae) that can burst and form open ulcers. […] With spider bites, complications are related to how venomous the particular spider involved is and/or how vulnerable or sensitive you are to the venom. […] There are five types of venomous spiders that cause the most risk for human, including the black widow, brown recluse, and hobo spider. The spider venoms are neurotoxic, meaning that they attack the nervous system. […] Anaphylaxis (a potentially life-threatening, whole-body allergy) can occur with spider bites. […] MRSA is an antibiotic-resistant bacteria that can be found in lots of community settings. If it’s not treated, it can enter the bloodstream and cause life-threatening infections.

• #90 Spider bites – Diagnosis & treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/spider-bites/diagnosis-treatment/drc-20352377

  Spider bites can be mistaken for other skin sores that are red, painful or swollen. […] Many skin sores attributed to spider bites turn out to have been caused by bites from other bugs, such as ants, fleas, mites, mosquitoes and biting flies. […] The process might involve determining whether anyone saw a spider bite you, having an expert identify the spider, and ruling out other possible causes of the signs and symptoms. […] Most spider bites usually heal on their own in about a week. […] A bite from a recluse spider takes longer to heal and sometimes leaves a scar. […] If the affected area is itchy, an antihistamine, such as diphenhydramine (Benadryl) or certirizine (Zyrtec), might help. […] You might need antibiotics if the bite develops into an open wound or becomes infected. […] If a black widow bite is causing severe pain or life-threatening symptoms, your doctor might recommend antivenom, which is usually given through a vein (intravenously).

• #91 Spider bites – Diagnosis & treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/spider-bites/diagnosis-treatment/drc-20352377

  Spider bites can be mistaken for other skin sores that are red, painful or swollen. […] Many skin sores attributed to spider bites turn out to have been caused by bites from other bugs, such as ants, fleas, mites, mosquitoes and biting flies. […] The process might involve determining whether anyone saw a spider bite you, having an expert identify the spider, and ruling out other possible causes of the signs and symptoms. […] Most spider bites usually heal on their own in about a week. […] A bite from a recluse spider takes longer to heal and sometimes leaves a scar. […] If the affected area is itchy, an antihistamine, such as diphenhydramine (Benadryl) or certirizine (Zyrtec), might help. […] You might need antibiotics if the bite develops into an open wound or becomes infected. […] If a black widow bite is causing severe pain or life-threatening symptoms, your doctor might recommend antivenom, which is usually given through a vein (intravenously).

• #92 Bites and Stings: Pictures, Causes, Symptoms, and Treatment

  https://www.healthline.com/health/bug-bites

  Most spiders dont pose a threat to humans, and in such cases, their bites are harmless or mildly irritating like a bee sting. […] Dangerous spiders include the brown recluse, black widow, funnel web spider (Australia), and wandering spider (South America). […] A single raised papule, pustule, or wheal may appear at the site of the bite followed by redness and tenderness. […] Severe allergic reactions to a spider bite may require medical attention. […] It is deemed non-aggressive and will only bite humans if its being crushed between the skin and a hard surface. […] Rare complications include fever, body aches, nausea, vomiting, hemolytic anemia, rhabdomyolysis, and kidney failure. […] A bite from a black widow spider causes a sharp pain, like a pin prick. This is followed by dull, sometimes numbing pain around the site.

• #93 Spider Bites, Bug Bites, or MRSA: Causes of Blisters

  https://www.verywellhealth.com/spider-bite-or-skin-infection-83017

  Spider bites and other insect bites can cause pus blisters, but so can a potentially serious infection known as methicillin-resistant Staphylococcus aureus (MRSA). […] Spider bite symptoms can vary from person to person as well as by species. Typically, spider bites result in fluid-filled blisters (bullae) that can burst and form open ulcers. […] With spider bites, complications are related to how venomous the particular spider involved is and/or how vulnerable or sensitive you are to the venom. […] There are five types of venomous spiders that cause the most risk for human, including the black widow, brown recluse, and hobo spider. The spider venoms are neurotoxic, meaning that they attack the nervous system. […] Anaphylaxis (a potentially life-threatening, whole-body allergy) can occur with spider bites. […] MRSA is an antibiotic-resistant bacteria that can be found in lots of community settings. If it’s not treated, it can enter the bloodstream and cause life-threatening infections.

• #94 Treating Swelling and Allergic Reactions to Spider and Insect Bites

  https://www.webmd.com/first-aid/understanding-insect-bites-spider-bites-basic-information

  A sting happens when an insect injects venom into your skin. […] Ticks and some spiders also bite, but technically they are arachnids, not insects. Ticks feed on your blood, but spiders do not. Also, some spiders have venom. […] Rarely, a spider bite can cause an allergic reaction that doctors call anaphylactic shock. It can be fatal.

• #95 Hand–Foot Syndrome Caused by Brown Spider Bite | HTML | Acta Dermato-Venereologica

  https://www.medicaljournals.se/acta/content/html/10.1080/00015555-0082

  Handfoot syndrome (HFS) is a rare erythematous skin lesion of the palmoplantar areas of hands and feet. […] Our case is the first report in the medical literature that documents HFS as a result of spider bite. […] The brown recluse spider of genus Loxosceles is also known as the violin or fiddleback spider (L. reclusa) because of a violin-shaped mark on its head. […] The brown recluse spiders bites usually causes some pain or burning in the first 10 min, accompanied by itching. […] Brown spider bites may go unnoticed, cause a mild local reaction (see above), or a severe local reaction in a few cases. […] HFS as a complication of spider bite has never been described in the literature. […] While the occurrence and incidence is known to be dose dependent (9) the exact pathogenesis remains obscure. […] It has been hypothesized that HFS is an inflammatory phenomenon mediated by over-expression of cyclo-oxygenase 2 (COX-2) (7).

• #96 Spider Bites Treatment Santa Ana – Bristol & First Medical Clinic

  https://firstandbristolmedical.com/spider-bites/

  Spider bites can cause a great deal of stress, since some spider bites contain venom that can cause a person to feel sick or that can even be life threatening. […] While most spider bites are not serious, the bites from some types of spiders can cause ill effects in humans. And in some rare cases, spider bites can be fatal (usually when the person bitten is very young or very old, or has a weak immune system). […] Black widow spider bites can be fatal to humans, but fatal black widow bites are rare. […] Brown recluse spider bites are rarely fatal. However, brown recluse bites can be painful and can cause highly unpleasant symptoms. […] The tarantula, a spider known for its large size and hairy body, has a venomous bite. However, this type of spider bite is very rare, since tarantulas rarely bite humans.

• #97 Spider Bites

  https://healthlibrary.brighamandwomens.org/library/diseasesconditions/adult/NonTraumatic/85,P00860

  Most spiders found in the U.S. are harmless, except for the brown recluse and the black widow spiders. […] Venom from the brown recluse spider often causes local skin tissue damage. […] Black widow spider bites release a poison that can damage the nervous system. Emergency care is needed right away. […] Symptoms of a brown recluse spider bite include a deep blue or purple area around the bite, surrounded by a whitish ring and large red outer ring like a target or bulls-eye. […] Symptoms of a black widow spider bite include cramping pain and muscle stiffness. There may also be weakness, tremors, or paralysis, especially in the legs. […] Prompt treatment of both types of spider bites is key to preventing more serious complications, especially in children.

• #98 What Should I do if I Get a Spider Bite? – familydoctor.org

  https://familydoctor.org/spider-bites/

  Spiders are found everywhere. But each kind of spider is unique. Some tend to live outdoors. Some are common inside the house. Either way, you may accidently bother a spider—and get bit. […] The majority of spiders in the U.S. aren’t dangerous or poisonous. Most spiders won’t bite you if you don’t bother them. If you do get bit, your symptoms will vary, depending on what type of spider bit you. […] Two spiders in the United States have venom that can cause severe skin and health issues. Venom is a fluid that spiders put into their victims when they bite them. This venom is what causes a reaction in your body. The two poisonous spiders that live in the U.S. are the black widow and the brown recluse. […] Black widow spiders are mostly found in the southern and western parts of the United States. […] Brown recluse spiders are most common in the Midwest and southern parts of the United States. […] Prevention is the key to avoiding spider bites. Remember, most spiders only bite when they feel threatened. Be aware of where spiders may live and be careful when in those areas.

• #99 Spider Bites — Louisville Lectures

  http://www.louisvillelectures.org/the-ll-blog-1/spiderbites/lehto

  Patients often present to the emergency with a variety of skin findings and worries about spider bites. In the United States, the two spiders that people are often worried about are the black widow (Latrodectus mactans) and the brown recluse (Loxosceles reclusa). Fortunately, there are only about 500 bites a year in the United States and deaths are very rare. […] The venom lacks human cytotoxic agents, so there is no local tissue injury and little to no local tenderness. The venom causes the release of norepinephrine, Gamma-Aminobutyric Acid, and acetylcholine via exocytosis of synaptic vesicles. It also leads to degeneration of motor endplates which leads to denervation as well as destabilization of nerve cell membranes, which causes a massive influx of calcium into the cells resulting in hypocalcemia.

• #100 Spider Bites

  https://healthlibrary.uwmedicine.org/Library/DiseasesConditions/Adult/Pathology/85,P00860

  Most spiders found in the U.S. are harmless, except for the brown recluse and the black widow spiders. […] Venom from the brown recluse spider often causes local skin tissue damage. […] Black widow spider bites release a poison that can damage the nervous system. Emergency care is needed right away. […] Symptoms of a brown recluse spider bite include a deep blue or purple area around the bite, surrounded by a whitish ring and large red outer ring like a target or bulls-eye. […] Symptoms of a black widow spider bite include cramping pain and muscle stiffness. There may also be weakness, tremors, or paralysis, especially in the legs.

• #101 Spider Bites: Symptoms, Causes, and Treatment | Red Cross

  https://www.redcross.org/take-a-class/resources/learn-first-aid/spider-bites?srsltid=AfmBOoqUJYGZpG2oqKD2JP7aBnU_QWPguFWEDrarPefuDgrxUvsrOLMg

  Few spiders in the United States can cause serious illness or death. […] The bites of the black widow and brown recluse spiders can, in rare cases, kill a person. […] Signs and symptoms of spider bites depend on the amount of venom injected and the persons sensitivity to the venom. […] The only way to be certain that a spider has bitten a person is to have witnessed it. […] Bites of black widow spiders can cause an immediate sharp pinprick pain, followed by a dull pain. Bites of brown recluse spiders may be painless at first; after an hour, pain may develop, followed by a blood-filled blister. […] This is a myth. None of these measures help slow the spread of venom but are likely to cause pain and injury. Seek medical attention as quickly as possible.

• #102 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Contrary to popular belief, hobo spider bites probably aren’t dangerous. […] Their venom doesn’t damage cells, and they don’t seem to carry harmful bacteria. […] In the past, people thought that wolf spider bites caused large, festering wounds. […] More recent evidence has shown that isn’t the case. […] Most times, spider bites are mild and get better on their own. […] But sometimes, they can cause more serious reactions. […] Dangerous reactions are more common among children, people older than 60, and people who have medical conditions.

• #103 Identifying Spider Bites: Symptoms & Treatment | UPMC HealthBeat

  https://share.upmc.com/2014/10/identifying-spider-bites/

  Most common spiders have fangs that are either too short or too fragile to break through human skin. Often, their venom is not poisonous enough to cause damage. […] There are two specific spiders in the United States the brown recluse and the black widow that can cause serious and even fatal illnesses. It is important to be able to identify these spider bites in order to seek proper treatment. […] The brown recluse spider is usually found in warm, dry climates. […] The initial bite is usually painless but within 8 hours you may notice: […] Brown recluse spider bite symptoms may include: […] Death is also a rare result of brown recluse spider bites and is more common with children. […] Black widow spider bites require immediate medical attention. […] Black widow spider venom is toxic and can cause damage to the nervous system. […] In rare cases, bites can result in death mostly in children, the extremely ill, and the elderly. […] Symptoms caused by a poisonous spider bite are much worse than those of a common spider bite.

• #104 Spider Bites | Boston Children’s Hospital

  https://www.childrenshospital.org/conditions/spider-bites

  It is estimated that less than three deaths per year occur from spider bites. However, most victims are children. Most of the 20,000 species of spiders found in the United States are poisonous, but their fangs are too short or too fragile to break through human skin. The bites of most spiders cause only minor, local reactions. […] In the United States, the two spiders that can cause serious problems are the black widow spider and the brown recluse spider (sometimes called the violin spider). Both of these spiders are found in warm climates. […] A black widow spider is a small, shiny black button-shaped spider with a red hourglass mark on its abdomen and that prefers warm climates. Widow spider bites release a toxin that can cause damage to the nervous system, thus, emergency medical treatment is necessary.

• #105 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Contrary to popular belief, hobo spider bites probably aren’t dangerous. […] Their venom doesn’t damage cells, and they don’t seem to carry harmful bacteria. […] In the past, people thought that wolf spider bites caused large, festering wounds. […] More recent evidence has shown that isn’t the case. […] Most times, spider bites are mild and get better on their own. […] But sometimes, they can cause more serious reactions. […] Dangerous reactions are more common among children, people older than 60, and people who have medical conditions.

• #106 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Contrary to popular belief, hobo spider bites probably aren’t dangerous. […] Their venom doesn’t damage cells, and they don’t seem to carry harmful bacteria. […] In the past, people thought that wolf spider bites caused large, festering wounds. […] More recent evidence has shown that isn’t the case. […] Most times, spider bites are mild and get better on their own. […] But sometimes, they can cause more serious reactions. […] Dangerous reactions are more common among children, people older than 60, and people who have medical conditions.

• #107 How to Identify and Treat Spider Bites

  https://www.everydayhealth.com/bug-bites/spider-bites/

  Spider bites are uncommon, and doctors often misdiagnose them. […] Spider bites are really rare, says Jonathan Day, PhD, a professor emeritus of medical entomology at the University of Florida in Gainesville. He explains that most spider bites are more likely mosquito bites that were scratched and developed into an infection. […] There are characteristic signs and symptoms when it comes to venomous spider bites. Brown recluse bites sting, and they can resemble anything from small blisters to large, rotting-flesh sores, Vetter says. Its bite causes the collapse of the capillary bed also known as skin necrosis so people who are obese and have poor support of the capillary cells may have a more massive reaction, he explains. Along with a wide variety of skin symptoms, brown recluse bites can cause symptoms common to infections. The brown recluse’s bite is poisonous and can result in coma, kidney failure, or even death. […] Black widow bites contain potentially deadly amounts of venom and tend to cause immediate pain around the bite site. […] Vetter says spiders bite people only in self-defense. […] So while spider bites do occur, they’re far less common than most people assume.

• #108 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  The brown recluse-the spider most commonly implicated in alleged bites-lives and breeds predominantly in the south central United States. Yet complaints of brown recluse spider bites are ubiquitous. […] When confronted with evidence of geographic improbability, patients with an alleged brown recluse spider bite commonly respond that the spider was recently imported from an area where it is endemic. […] Consider empiric antibiotic therapy for idiopathic dermonecrotic skin lesions because many of these lesions are caused by bacterial infection.

• #109 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Spiders live all over the United States. […] Spider bites are fairly uncommon. […] If a spider does bite you, it usually isn’t a problem. […] The CDC says only two venomous spiders that are native to the United States can do real harm when they bite a person: black widows and brown recluses. […] Black widow spiders live throughout the United States but are most common in the South and West. […] Only female black widows have neurotoxic venom. […] Brown recluse spiders live in the Midwest and South. […] Brown recluse venom can severely damage skin, causing a necrotic wound (a wound in which tissue dies). […] For years, people mistakenly believed that hobo spiders caused dangerous wounds. […] In reality, about 10% of brown recluse spider bites cause severe skin damage. […] Brown recluse spiders have a bad reputation for causing large, festering wounds.

• #110 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Spiders live all over the United States. […] Spider bites are fairly uncommon. […] If a spider does bite you, it usually isn’t a problem. […] The CDC says only two venomous spiders that are native to the United States can do real harm when they bite a person: black widows and brown recluses. […] Black widow spiders live throughout the United States but are most common in the South and West. […] Only female black widows have neurotoxic venom. […] Brown recluse spiders live in the Midwest and South. […] Brown recluse venom can severely damage skin, causing a necrotic wound (a wound in which tissue dies). […] For years, people mistakenly believed that hobo spiders caused dangerous wounds. […] In reality, about 10% of brown recluse spider bites cause severe skin damage. […] Brown recluse spiders have a bad reputation for causing large, festering wounds.

• #111 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  The brown recluse-the spider most commonly implicated in alleged bites-lives and breeds predominantly in the south central United States. Yet complaints of brown recluse spider bites are ubiquitous. […] When confronted with evidence of geographic improbability, patients with an alleged brown recluse spider bite commonly respond that the spider was recently imported from an area where it is endemic. […] Consider empiric antibiotic therapy for idiopathic dermonecrotic skin lesions because many of these lesions are caused by bacterial infection.

• #112 Spider Bites, Bug Bites, or MRSA: Causes of Blisters

  https://www.verywellhealth.com/spider-bite-or-skin-infection-83017

  Spider bites and other insect bites can cause pus blisters, but so can a potentially serious infection known as methicillin-resistant Staphylococcus aureus (MRSA). […] Spider bite symptoms can vary from person to person as well as by species. Typically, spider bites result in fluid-filled blisters (bullae) that can burst and form open ulcers. […] With spider bites, complications are related to how venomous the particular spider involved is and/or how vulnerable or sensitive you are to the venom. […] There are five types of venomous spiders that cause the most risk for human, including the black widow, brown recluse, and hobo spider. The spider venoms are neurotoxic, meaning that they attack the nervous system. […] Anaphylaxis (a potentially life-threatening, whole-body allergy) can occur with spider bites. […] MRSA is an antibiotic-resistant bacteria that can be found in lots of community settings. If it’s not treated, it can enter the bloodstream and cause life-threatening infections.

• #113 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  A spider bite, also known as arachnidism, is an injury resulting from the bite of a spider. The effects of most bites are not serious. Most bites result in mild symptoms around the area of the bite. Rarely they may produce a necrotic skin wound or severe pain. Most spiders do not cause bites that are of importance. For a bite to be significant, substantial envenomation is required. Bites from the widow spiders involve a neurotoxic venom which produces a condition known as latrodectism. Symptoms may include pain which may be at the bite or involve the chest and abdomen, sweating, muscle cramps and vomiting among others. Bites from the recluse spiders cause the condition loxoscelism, in which local necrosis of the surrounding skin and widespread breakdown of red blood cells may occur. Headaches, vomiting and a mild fever may also occur. Other spiders that can cause significant bites include the Australian funnel-web spider and South American wandering spider.

• #114 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  A spider bite, also known as arachnidism, is an injury resulting from the bite of a spider. The effects of most bites are not serious. Most bites result in mild symptoms around the area of the bite. Rarely they may produce a necrotic skin wound or severe pain. Most spiders do not cause bites that are of importance. For a bite to be significant, substantial envenomation is required. Bites from the widow spiders involve a neurotoxic venom which produces a condition known as latrodectism. Symptoms may include pain which may be at the bite or involve the chest and abdomen, sweating, muscle cramps and vomiting among others. Bites from the recluse spiders cause the condition loxoscelism, in which local necrosis of the surrounding skin and widespread breakdown of red blood cells may occur. Headaches, vomiting and a mild fever may also occur. Other spiders that can cause significant bites include the Australian funnel-web spider and South American wandering spider.

• #115 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  The brown recluse-the spider most commonly implicated in alleged bites-lives and breeds predominantly in the south central United States. Yet complaints of brown recluse spider bites are ubiquitous. […] When confronted with evidence of geographic improbability, patients with an alleged brown recluse spider bite commonly respond that the spider was recently imported from an area where it is endemic. […] Consider empiric antibiotic therapy for idiopathic dermonecrotic skin lesions because many of these lesions are caused by bacterial infection.

• #116 Spider Bites | Boston Children’s Hospital

  https://www.childrenshospital.org/conditions/spider-bites

  It is estimated that less than three deaths per year occur from spider bites. However, most victims are children. Most of the 20,000 species of spiders found in the United States are poisonous, but their fangs are too short or too fragile to break through human skin. The bites of most spiders cause only minor, local reactions. […] In the United States, the two spiders that can cause serious problems are the black widow spider and the brown recluse spider (sometimes called the violin spider). Both of these spiders are found in warm climates. […] A black widow spider is a small, shiny black button-shaped spider with a red hourglass mark on its abdomen and that prefers warm climates. Widow spider bites release a toxin that can cause damage to the nervous system, thus, emergency medical treatment is necessary.

• #117 Spider Bites | Boston Children’s Hospital

  https://www.childrenshospital.org/conditions/spider-bites

  It is estimated that less than three deaths per year occur from spider bites. However, most victims are children. Most of the 20,000 species of spiders found in the United States are poisonous, but their fangs are too short or too fragile to break through human skin. The bites of most spiders cause only minor, local reactions. […] In the United States, the two spiders that can cause serious problems are the black widow spider and the brown recluse spider (sometimes called the violin spider). Both of these spiders are found in warm climates. […] A black widow spider is a small, shiny black button-shaped spider with a red hourglass mark on its abdomen and that prefers warm climates. Widow spider bites release a toxin that can cause damage to the nervous system, thus, emergency medical treatment is necessary.

• #118 Spider Bites Treatment Santa Ana – Bristol & First Medical Clinic

  https://firstandbristolmedical.com/spider-bites/

  Spider bites can cause a great deal of stress, since some spider bites contain venom that can cause a person to feel sick or that can even be life threatening. […] While most spider bites are not serious, the bites from some types of spiders can cause ill effects in humans. And in some rare cases, spider bites can be fatal (usually when the person bitten is very young or very old, or has a weak immune system). […] Black widow spider bites can be fatal to humans, but fatal black widow bites are rare. […] Brown recluse spider bites are rarely fatal. However, brown recluse bites can be painful and can cause highly unpleasant symptoms. […] The tarantula, a spider known for its large size and hairy body, has a venomous bite. However, this type of spider bite is very rare, since tarantulas rarely bite humans.

• #119 Spider Bites Treatment Santa Ana – Bristol & First Medical Clinic

  https://firstandbristolmedical.com/spider-bites/

  Spider bites can cause a great deal of stress, since some spider bites contain venom that can cause a person to feel sick or that can even be life threatening. […] While most spider bites are not serious, the bites from some types of spiders can cause ill effects in humans. And in some rare cases, spider bites can be fatal (usually when the person bitten is very young or very old, or has a weak immune system). […] Black widow spider bites can be fatal to humans, but fatal black widow bites are rare. […] Brown recluse spider bites are rarely fatal. However, brown recluse bites can be painful and can cause highly unpleasant symptoms. […] The tarantula, a spider known for its large size and hairy body, has a venomous bite. However, this type of spider bite is very rare, since tarantulas rarely bite humans.

• #120 Black Widow Spider Bite Treatment

  https://my.clevelandclinic.org/health/diseases/black-widow-spider-bite

  Female black widow spiders may bite in defense, especially after they lay eggs. […] Most spider bites are accidents. If you accidentally brush up against a spider, it’s just trying to defend itself. They don’t purposely try to attack you. […] Black widow spider bites typically occur when humans come into direct contact with their webs. They only bite when threatened. […] Black widow spiders have large fangs and glands that produce very toxic venom. When bitten, the venom attacks the nerve endings in your muscles, causing symptoms such as severe, bodywide muscle pain and cramping. […] A black widow spider bite causes a sharp, pinprick-like pain. A dull numbness in the bite area may follow. Black widow spider venom interferes with chemicals in your nerve endings. This can produce severe pain, stiffness and muscle spasms throughout your body, including your belly (abdomen), shoulders, chest and back. […] Rarely, some people have long-term pain or muscle spasms after black widow spider bites.

• #121 How to Identify Spider Bites | Spider Bite Facts | Orkin

  https://www.orkin.com/pests/spiders/what-do-spider-bites-look-like

  The most important effect of their bites is the effect on the victims central nervous system. […] Symptoms will include intense localized pain, muscle cramps and pain, increased blood pressure, profuse sweating, nausea, and sometimes a skin rash. […] Normally the bite symptoms are localized, but this spider groups bites may sometimes cause systemic reactions such as anemia, blood in the urine, fever, rash, nausea, vomiting, and even coma in very rare instances. […] All spiders with the exception of those in the family Uloboridae use their venom to paralyze or kill prey they must consume in order to survive. […] Spider publications generally report that only about 50 species of spiders are implicated in bites that are likely to cause medical implications beyond temporary localized pain and slight swelling at the site of the bite.

• #122 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  Management. Brown recluse spider bites have been treated with antibiotics, antihistamines, corticosteroids, dapsone, hyperbaric oxygen, nitroglycerine patches, surgical excision, and even direct high-voltage current from a stun gun. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive; it includes microbial infections, dermatologic disorders, vasculitides, and environmental exposures. […] We use the term „idiopathic dermonecrotic skin lesion” for lesions ascribed to spider bites that defy easy diagnosis. […] Most patients with alleged spider bites have bacterial cellulitis, which is often caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). […] Patients with a CA-MRSA infection who claim to have a spider bite rarely report feeling a bite or seeing a spider and often admit that a friend or family member suggested this was the cause.

• #123 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  The bites of only a few spider species produce medically significant effects in humans. […] Patients often attribute the otherwise unexplained development of a dermonecrotic lesion to a spider bite. This self-diagnosis is rarely corroborated by evidence, however. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive. Most of the conditions in the differential are far more common than spider bites. […] Thus, we suggest that you approach the complaint of a „spider bite” with a skeptical eye. […] Spiders have complex and specialized feeding strategies; they often use webs to capture and eat insects and other small arthropods. Unlike insects that feed on human blood or serum, spiders have no reason to bite humans. Thus, a spider bite must be considered an anomaly that probably resulted from human actions which induced the arthropod to bite in self-defense.

• #124 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  Management. Brown recluse spider bites have been treated with antibiotics, antihistamines, corticosteroids, dapsone, hyperbaric oxygen, nitroglycerine patches, surgical excision, and even direct high-voltage current from a stun gun. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive; it includes microbial infections, dermatologic disorders, vasculitides, and environmental exposures. […] We use the term „idiopathic dermonecrotic skin lesion” for lesions ascribed to spider bites that defy easy diagnosis. […] Most patients with alleged spider bites have bacterial cellulitis, which is often caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). […] Patients with a CA-MRSA infection who claim to have a spider bite rarely report feeling a bite or seeing a spider and often admit that a friend or family member suggested this was the cause.

• #125 Spider bites

  https://dermnetnz.org/topics/spider-bite

  The venom produced by spider bites is generally either neurotoxic or cytotoxic. […] The signs and symptoms from a bite from a spider with neurotoxic venom differ to those produced by a spider with cytotoxic venom. […] Although many people attribute an episode of bacterial infection (especially cellulitis and necrotising fasciitis) to an unseen spider bite, they are falsely blamed. Documented spider bites have not led to skin these infections. […] One of the most important aspects in treating spider bites it to try and identify the offending spider. The venom of spider bites is quite variable hence identification of the spider can be of value in determining the management of the condition.

• #126 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  Management. Brown recluse spider bites have been treated with antibiotics, antihistamines, corticosteroids, dapsone, hyperbaric oxygen, nitroglycerine patches, surgical excision, and even direct high-voltage current from a stun gun. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive; it includes microbial infections, dermatologic disorders, vasculitides, and environmental exposures. […] We use the term „idiopathic dermonecrotic skin lesion” for lesions ascribed to spider bites that defy easy diagnosis. […] Most patients with alleged spider bites have bacterial cellulitis, which is often caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). […] Patients with a CA-MRSA infection who claim to have a spider bite rarely report feeling a bite or seeing a spider and often admit that a friend or family member suggested this was the cause.

• #127 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  Management. Brown recluse spider bites have been treated with antibiotics, antihistamines, corticosteroids, dapsone, hyperbaric oxygen, nitroglycerine patches, surgical excision, and even direct high-voltage current from a stun gun. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive; it includes microbial infections, dermatologic disorders, vasculitides, and environmental exposures. […] We use the term „idiopathic dermonecrotic skin lesion” for lesions ascribed to spider bites that defy easy diagnosis. […] Most patients with alleged spider bites have bacterial cellulitis, which is often caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). […] Patients with a CA-MRSA infection who claim to have a spider bite rarely report feeling a bite or seeing a spider and often admit that a friend or family member suggested this was the cause.

• #128 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  Management. Brown recluse spider bites have been treated with antibiotics, antihistamines, corticosteroids, dapsone, hyperbaric oxygen, nitroglycerine patches, surgical excision, and even direct high-voltage current from a stun gun. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive; it includes microbial infections, dermatologic disorders, vasculitides, and environmental exposures. […] We use the term „idiopathic dermonecrotic skin lesion” for lesions ascribed to spider bites that defy easy diagnosis. […] Most patients with alleged spider bites have bacterial cellulitis, which is often caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). […] Patients with a CA-MRSA infection who claim to have a spider bite rarely report feeling a bite or seeing a spider and often admit that a friend or family member suggested this was the cause.

• #129 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  Management. Brown recluse spider bites have been treated with antibiotics, antihistamines, corticosteroids, dapsone, hyperbaric oxygen, nitroglycerine patches, surgical excision, and even direct high-voltage current from a stun gun. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive; it includes microbial infections, dermatologic disorders, vasculitides, and environmental exposures. […] We use the term „idiopathic dermonecrotic skin lesion” for lesions ascribed to spider bites that defy easy diagnosis. […] Most patients with alleged spider bites have bacterial cellulitis, which is often caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). […] Patients with a CA-MRSA infection who claim to have a spider bite rarely report feeling a bite or seeing a spider and often admit that a friend or family member suggested this was the cause.

• #130 Spider bites – Diagnosis & treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/spider-bites/diagnosis-treatment/drc-20352377

  Spider bites can be mistaken for other skin sores that are red, painful or swollen. […] Many skin sores attributed to spider bites turn out to have been caused by bites from other bugs, such as ants, fleas, mites, mosquitoes and biting flies. […] The process might involve determining whether anyone saw a spider bite you, having an expert identify the spider, and ruling out other possible causes of the signs and symptoms. […] Most spider bites usually heal on their own in about a week. […] A bite from a recluse spider takes longer to heal and sometimes leaves a scar. […] If the affected area is itchy, an antihistamine, such as diphenhydramine (Benadryl) or certirizine (Zyrtec), might help. […] You might need antibiotics if the bite develops into an open wound or becomes infected. […] If a black widow bite is causing severe pain or life-threatening symptoms, your doctor might recommend antivenom, which is usually given through a vein (intravenously).

• #131 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  Management. Brown recluse spider bites have been treated with antibiotics, antihistamines, corticosteroids, dapsone, hyperbaric oxygen, nitroglycerine patches, surgical excision, and even direct high-voltage current from a stun gun. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive; it includes microbial infections, dermatologic disorders, vasculitides, and environmental exposures. […] We use the term „idiopathic dermonecrotic skin lesion” for lesions ascribed to spider bites that defy easy diagnosis. […] Most patients with alleged spider bites have bacterial cellulitis, which is often caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). […] Patients with a CA-MRSA infection who claim to have a spider bite rarely report feeling a bite or seeing a spider and often admit that a friend or family member suggested this was the cause.

• #132 Spider Bites | Disease Outbreak Control Division

  https://health.hawaii.gov/docd/disease_listing/spider-bites/

  Spider bites may occur when humans come into direct contact with spiders when working in the garden, outdoors and around the home. […] Diagnosis of spider bite is based on recent history and signs and symptoms. Specific diagnosis may be difficult to confirm without identification of the spider. […] Though rare, spider bites do occur. Your risk of being bitten increases if you live in areas where there is clutter and debris or if their habitat has been disturbed.

• #133 Spider Bites | VCA Canada Animal Hospitals

  https://vcahospitals.com/know-your-pet/spider-bites

  Female black widows are significantly larger and more venomous than males. […] The effects of black widow and brown recluse spider bites vary significantly due to differences in the venom of these two types of spiders. […] Black widow spider venom contains a neurotoxin. This substance causes massive excitation of neurons (the cells within the nervous system), leading to muscle tremors and other effects seen in black widow envenomation. […] Brown recluse spider venom, in contrast, contains several substances that trigger local tissue effects. The first part of brown recluse venom contains a substance known as sphingomyelinase D, which interferes with blood clotting at the site of the bite. Additional toxins are injected into the bite victim, contributing to local inflammation and tissue necrosis. […] The only way to definitively diagnose a spider bite is to collect and identify the spider responsible for causing the bite.

• #134 How to Identify and Treat Spider Bites

  https://www.everydayhealth.com/bug-bites/spider-bites/

  Spider bites are uncommon, and doctors often misdiagnose them. […] Spider bites are really rare, says Jonathan Day, PhD, a professor emeritus of medical entomology at the University of Florida in Gainesville. He explains that most spider bites are more likely mosquito bites that were scratched and developed into an infection. […] There are characteristic signs and symptoms when it comes to venomous spider bites. Brown recluse bites sting, and they can resemble anything from small blisters to large, rotting-flesh sores, Vetter says. Its bite causes the collapse of the capillary bed also known as skin necrosis so people who are obese and have poor support of the capillary cells may have a more massive reaction, he explains. Along with a wide variety of skin symptoms, brown recluse bites can cause symptoms common to infections. The brown recluse’s bite is poisonous and can result in coma, kidney failure, or even death. […] Black widow bites contain potentially deadly amounts of venom and tend to cause immediate pain around the bite site. […] Vetter says spiders bite people only in self-defense. […] So while spider bites do occur, they’re far less common than most people assume.

• #135 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  The bites of only a few spider species produce medically significant effects in humans. […] Patients often attribute the otherwise unexplained development of a dermonecrotic lesion to a spider bite. This self-diagnosis is rarely corroborated by evidence, however. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive. Most of the conditions in the differential are far more common than spider bites. […] Thus, we suggest that you approach the complaint of a „spider bite” with a skeptical eye. […] Spiders have complex and specialized feeding strategies; they often use webs to capture and eat insects and other small arthropods. Unlike insects that feed on human blood or serum, spiders have no reason to bite humans. Thus, a spider bite must be considered an anomaly that probably resulted from human actions which induced the arthropod to bite in self-defense.

• #136 Spider bites – Diagnosis & treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/spider-bites/diagnosis-treatment/drc-20352377

  Spider bites can be mistaken for other skin sores that are red, painful or swollen. […] Many skin sores attributed to spider bites turn out to have been caused by bites from other bugs, such as ants, fleas, mites, mosquitoes and biting flies. […] The process might involve determining whether anyone saw a spider bite you, having an expert identify the spider, and ruling out other possible causes of the signs and symptoms. […] Most spider bites usually heal on their own in about a week. […] A bite from a recluse spider takes longer to heal and sometimes leaves a scar. […] If the affected area is itchy, an antihistamine, such as diphenhydramine (Benadryl) or certirizine (Zyrtec), might help. […] You might need antibiotics if the bite develops into an open wound or becomes infected. […] If a black widow bite is causing severe pain or life-threatening symptoms, your doctor might recommend antivenom, which is usually given through a vein (intravenously).

• #137 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  Management. Brown recluse spider bites have been treated with antibiotics, antihistamines, corticosteroids, dapsone, hyperbaric oxygen, nitroglycerine patches, surgical excision, and even direct high-voltage current from a stun gun. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive; it includes microbial infections, dermatologic disorders, vasculitides, and environmental exposures. […] We use the term „idiopathic dermonecrotic skin lesion” for lesions ascribed to spider bites that defy easy diagnosis. […] Most patients with alleged spider bites have bacterial cellulitis, which is often caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). […] Patients with a CA-MRSA infection who claim to have a spider bite rarely report feeling a bite or seeing a spider and often admit that a friend or family member suggested this was the cause.

• #138 What Should I do if I Get a Spider Bite? – familydoctor.org

  https://familydoctor.org/spider-bites/

  Spiders are found everywhere. But each kind of spider is unique. Some tend to live outdoors. Some are common inside the house. Either way, you may accidently bother a spider—and get bit. […] The majority of spiders in the U.S. aren’t dangerous or poisonous. Most spiders won’t bite you if you don’t bother them. If you do get bit, your symptoms will vary, depending on what type of spider bit you. […] Two spiders in the United States have venom that can cause severe skin and health issues. Venom is a fluid that spiders put into their victims when they bite them. This venom is what causes a reaction in your body. The two poisonous spiders that live in the U.S. are the black widow and the brown recluse. […] Black widow spiders are mostly found in the southern and western parts of the United States. […] Brown recluse spiders are most common in the Midwest and southern parts of the United States. […] Prevention is the key to avoiding spider bites. Remember, most spiders only bite when they feel threatened. Be aware of where spiders may live and be careful when in those areas.

• #139 Spider bites // Middlesex Health

  https://middlesexhealth.org/learning-center/diseases-and-conditions/spider-bites

  Spider bites can cause redness, pain and swelling, or you might not notice them at all. […] Worldwide only a few species of spiders have fangs long enough to penetrate human skin and venom strong enough to hurt humans. […] Severe spider bite symptoms occur as a result of the venom that the spider injects. Symptom severity depends on the type of spider, the amount of venom injected and how sensitive your body is to the venom.

• #140 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. […] A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites involve injection of venom, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider could inject when biting. While venoms are by definition toxic substances, most spiders do not have venom that is directly toxic (in the quantities delivered) to require medical attention and, of those that do, severity is typically mild. Spider venoms work on one of two fundamental principles; they are either neurotoxic (attacking the nervous system) or necrotic (attacking tissues surrounding the bite). In some cases, the venom affects vital organs and systems. The venoms of the widow spiders, Brazilian wandering spider and Australian funnel-web are neurotoxic. Heart muscle damage is an unusual complication of widow venom that may lead to death. Pulmonary edema, which is fluid accumulation in the lungs, is a feared and potentially serious but uncommon complication of funnel-web venom. Recluse and South African sand spider venoms are necrotic. Recluse venom may also cause severe hemolysis (destruction of red blood cells), though this is typically uncommon.

• #141 Spider bites

  https://dermnetnz.org/topics/spider-bite

  The venom produced by spider bites is generally either neurotoxic or cytotoxic. […] The signs and symptoms from a bite from a spider with neurotoxic venom differ to those produced by a spider with cytotoxic venom. […] Although many people attribute an episode of bacterial infection (especially cellulitis and necrotising fasciitis) to an unseen spider bite, they are falsely blamed. Documented spider bites have not led to skin these infections. […] One of the most important aspects in treating spider bites it to try and identify the offending spider. The venom of spider bites is quite variable hence identification of the spider can be of value in determining the management of the condition.

• #142 Spider bite – Wikipedia

  https://en.wikipedia.org/wiki/Spider_bite

  Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. […] A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin. Not all spider bites involve injection of venom, and the amount of venom injected can vary based on the type of spider and the circumstances of the encounter. The mechanical injury from a spider bite is not a serious concern for humans. However, it is generally the toxicity of spider venom that poses the most risk to human beings; several spiders are known to have venom that can cause injury to humans in the amounts that a spider could inject when biting. While venoms are by definition toxic substances, most spiders do not have venom that is directly toxic (in the quantities delivered) to require medical attention and, of those that do, severity is typically mild. Spider venoms work on one of two fundamental principles; they are either neurotoxic (attacking the nervous system) or necrotic (attacking tissues surrounding the bite). In some cases, the venom affects vital organs and systems. The venoms of the widow spiders, Brazilian wandering spider and Australian funnel-web are neurotoxic. Heart muscle damage is an unusual complication of widow venom that may lead to death. Pulmonary edema, which is fluid accumulation in the lungs, is a feared and potentially serious but uncommon complication of funnel-web venom. Recluse and South African sand spider venoms are necrotic. Recluse venom may also cause severe hemolysis (destruction of red blood cells), though this is typically uncommon.

• #143 Spider bites // Middlesex Health

  https://middlesexhealth.org/learning-center/diseases-and-conditions/spider-bites

  Spider bites can cause redness, pain and swelling, or you might not notice them at all. […] Worldwide only a few species of spiders have fangs long enough to penetrate human skin and venom strong enough to hurt humans. […] Severe spider bite symptoms occur as a result of the venom that the spider injects. Symptom severity depends on the type of spider, the amount of venom injected and how sensitive your body is to the venom.

• #144 Get a Spider Bite? Here’s What You Need to Know

  https://www.webmd.com/skin-problems-and-treatments/what-to-know-about-spider-bites

  Contrary to popular belief, hobo spider bites probably aren’t dangerous. […] Their venom doesn’t damage cells, and they don’t seem to carry harmful bacteria. […] In the past, people thought that wolf spider bites caused large, festering wounds. […] More recent evidence has shown that isn’t the case. […] Most times, spider bites are mild and get better on their own. […] But sometimes, they can cause more serious reactions. […] Dangerous reactions are more common among children, people older than 60, and people who have medical conditions.

• #145 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  Management. Brown recluse spider bites have been treated with antibiotics, antihistamines, corticosteroids, dapsone, hyperbaric oxygen, nitroglycerine patches, surgical excision, and even direct high-voltage current from a stun gun. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive; it includes microbial infections, dermatologic disorders, vasculitides, and environmental exposures. […] We use the term „idiopathic dermonecrotic skin lesion” for lesions ascribed to spider bites that defy easy diagnosis. […] Most patients with alleged spider bites have bacterial cellulitis, which is often caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). […] Patients with a CA-MRSA infection who claim to have a spider bite rarely report feeling a bite or seeing a spider and often admit that a friend or family member suggested this was the cause.

• #146 Necrotic Skin Lesions: Spider Bite-or Something Else?

  https://www.patientcareonline.com/view/necrotic-skin-lesions-spider-biteor-something-else

  The bites of only a few spider species produce medically significant effects in humans. […] Patients often attribute the otherwise unexplained development of a dermonecrotic lesion to a spider bite. This self-diagnosis is rarely corroborated by evidence, however. […] Although spider bites can produce dermonecrotic wounds, the differential diagnosis of such lesions is extensive. Most of the conditions in the differential are far more common than spider bites. […] Thus, we suggest that you approach the complaint of a „spider bite” with a skeptical eye. […] Spiders have complex and specialized feeding strategies; they often use webs to capture and eat insects and other small arthropods. Unlike insects that feed on human blood or serum, spiders have no reason to bite humans. Thus, a spider bite must be considered an anomaly that probably resulted from human actions which induced the arthropod to bite in self-defense.

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