Materiały źródłowe

• #1 Urticaria (Hives): a complete overview — DermNet

  https://dermnetnz.org/topics/urticaria-an-overview

  What causes urticaria? Weals are due to release of chemical mediators from tissue mast cells and circulating basophils. These chemical mediators include histamine, platelet-activating factor and cytokines. The mediators activate sensory nerves and cause dilation of blood vessels and leakage of fluid into surrounding tissues. Bradykinin release causes angioedema. […] Several hypotheses have been proposed to explain urticaria. The immune, arachidonic acid and coagulation systems are involved, and genetic mutations are under investigation. […] Acute urticaria can be induced by the following factors, but the cause is not always identified. […] Chronic spontaneous urticaria is mainly idiopathic (cause unknown). An autoimmune cause is likely. About half of investigated patients carry functional IgG autoantibodies to immunoglobulin IgE or high-affinity receptor FcRI.

• #1 Hives – Wikipedia

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

  Hives frequently occur following an infection or as a result of an allergic reaction such as to medication, insect bites, or food. […] In half of cases the cause remains unknown. […] Hives can also be classified by the purported causative agent. Many different substances in the environment may cause hives, including medications, food and physical agents. In perhaps more than 50% of people with chronic hives of unknown cause, it is due to an autoimmune reaction. […] Over half of all cases of chronic idiopathic hives are the result of an autoimmune trigger. […] Hive-like rashes commonly accompany viral illnesses, such as the common cold. […] Mechanisms other than allergen-antibody interactions are known to cause histamine release from mast cells. […] Chronic idiopathic hives has been anecdotally linked to stress since the 1940s. […] A link between stress and this condition has also been shown.

• #1 Hives: Causes

  https://www.aad.org/public/diseases/a-z/hives-causes

  What causes hives? The often-itchy bumps and raised patches of hives develop when the body releases histamine. […] Sometimes, the immune system releases histamine when there is no real threat. This happens when people develop an allergic reaction. In fact, some people develop hives when they have an allergic reaction. […] When the body mistakenly releases histamine and hives develop, the cause is often one of the following: An allergic reaction, Overreaction to heat, sweat, or cold, Stress, Sunlight, Pressure on the skin (tight clothing, light touch of a purse strap, or scratching). […] When hives are due to an allergic reaction, it’s often an allergy to: A food, Bug bite or sting, Latex, Medication, Pet dander, Plant, Pollen. […] Some people get hives when they develop an infection like strep throat, a urinary tract infection, or COVID-19.

• #1 Hives and angioedema – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/hives-and-angioedema/symptoms-causes/syc-20354908

  Hives also known as urticaria (ur-tih-KAR-e-uh) is a skin reaction that causes itchy welts that range in size from small spots to large blotches. Hives can be triggered by many situations and substances, including certain foods and medications. […] For most people who experience acute hives and angioedema, the exact cause can’t be identified. The conditions are sometimes caused by: […] Many foods can trigger reactions in people with sensitivities. Shellfish, fish, peanuts, tree nuts, soy, eggs and milk are frequent offenders. […] Many medications may cause hives or angioedema, including penicillins, aspirin, ibuprofen (Advil, Motrin IB, others), naproxen sodium (Aleve) and blood pressure medications. […] Pollen and other allergens that you breathe in can trigger hives, sometimes accompanied by upper and lower respiratory tract symptoms. […] Other causes of acute hives and angioedema are insect bites and infections.

• #1 Acute and Chronic Urticaria: Evaluation and Treatment | AAFP

  https://www.aafp.org/pubs/afp/issues/2017/0601/p717.html

  Urticaria and angioedema have similar underlying pathophysiologic mechanisms: histamine and other mediators released from mast cells and basophils. If the release occurs in the dermis, it results in urticaria, whereas if the release occurs in the deeper dermis and subcutaneous tissues, it results in angioedema. Immunoglobulin E (IgE) often mediates this release, but non-IgE and nonimmunologic mast cell activation also can occur. Proteases from aeroallergens and activation of the complement system have been proposed as examples of non-IgE triggers. […] There are a number of identified causes of urticaria. Common causes include allergens, food pseudoallergens (foods that contain histamine or salicylates, or cause the release of histamine directly), insect envenomation, medications, and infections. Infections are the most common cause of urticaria in children. The infectious agents commonly associated with urticaria include various viruses (e.g., rhinovirus, rotavirus, Epstein-Barr, hepatitis A, hepatitis B, hepatitis C, herpes simplex, human immunodeficiency virus), bacteria (e.g., urinary tract infections, streptococcus, mycoplasma, Helicobacter pylori), and parasites. Medications, notably beta-lactam antibiotics, typically cause urticaria via allergic reactions, although some medications (e.g., aspirin, nonsteroidal anti-inflammatory drugs [NSAIDs], vancomycin, opiates) can also trigger urticaria through direct mast cell degranulation.

• #1 Hives – UF Health

  https://ufhealth.org/conditions-and-treatments/hives

  Hives are raised, often itchy, red bumps (welts) on the surface of the skin. They can be an allergic reaction to food or medicine. They can also appear without cause. […] When you have an allergic reaction to a substance, your body releases histamine and other chemicals into the blood. This causes itching, swelling, and other symptoms. Hives are a common reaction. People with other allergies, such as hay fever, often get hives. […] Many substances can trigger hives, including: Animal dander (especially cats), Insect bites, Medicines, Pollen, Shellfish, fish, nuts, eggs, milk, and other foods. […] Hives may also develop as a result of: Emotional stress, Extreme cold or sun exposure, Excessive perspiration, Illness, including lupus, other autoimmune diseases, and leukemia, Infections such as mononucleosis, Exercise, Exposure to water.

• #1 Hives (urticaria): Causes, pictures, and treatments

  https://www.medicalnewstoday.com/articles/157260

  Hives, or urticaria, can occur for many reasons, such as exposure to an allergen or a physical trigger, like pressure from tight clothing. It may also indicate an infection or another underlying health condition. […] Hives can develop when the body reacts to an allergen. When an allergic reaction occurs, the body releases a protein known as histamine. Next, tiny blood vessels called capillaries leak fluid. This fluid accumulates in the skin and causes inflammation and a rash. As fluid accumulates under the skin, small bumps form. […] If acute hives results from an allergic reaction, the cause may be: a medication, such as: some antibiotics, some nonsteroidal anti-inflammatory drugs, such as aspirin, angiotensin converting enzyme inhibitors, which are drugs for high blood pressure, nuts, eggs, seafood, or another food allergen, latex, kiwi, banana, chestnuts, or mango, in people with a latex allergy, some plants, including nettles, poison ivy, and poison oak, additives in some foods, cosmetics, and other products.

• #1 Hives (urticaria) – Australasian Society of Clinical Immunology and Allergy (ASCIA)

  https://www.allergy.org.au/patients/skin-allergy/urticaria-hives

  Hives occur when histamine is released in the lining of the skin and other body organs which makes the skin itch and causes blood vessels to expand and leak fluid. This results in redness and swelling. […] It is not always known what causes hives, but they are rarely due to a serious disease. Some common causes are: […] An allergic cause for hives should be suspected if episodes are rare, short-lived, and occur: […] Hives lasting longer than a few days are unlikely to be caused by an allergy, except in some cases of drug (medication) allergy. […] Stress is very rarely the cause of hives, but it can make symptoms worse. In some people, hives are caused by physical triggers including cold, heat, sunlight, vibration, rubbing, or scratching of the skin, and delayed pressure such as after carrying heavy bags or wearing tight clothing. In other people, exercise, sweating, stress, drinking alcohol or coffee, or eating spicy food may cause symptoms.

• #1 Hives: Causes, Symptoms and Treatments

  https://mydoctor.kaiserpermanente.org/mas/news/hives-causes-symptoms-and-treatments-2135045

  Hives appear when immune cells are activated and release histamine, a chemical that can cause redness and itching. […] Acute hives are most commonly caused by viral or bacterial infections, especially in children. Acute hives also can be triggered by heavy exercise, alcohol consumption, or animal dander and saliva. Other causes of hives include: Stress, Vaccines, Food allergies, such as allergies to peanuts and other nuts, eggs, shellfish, fish, milk, wheat and soy, Medication allergies, such as allergies to penicillin and other antibiotics, Insect bite stings. Stings from wasps, yellow jackets and hornets can cause hives in some people. Latex allergies. Latex is commonly found in condoms and some adhesive bandages. […] About 20 percent of people with chronic urticaria will have a physical trigger that causes the hives. This means that some people get hives from certain physical sensations that interact with their body.

• #1 Hives (Urticaria) Causes, Fast Treatment, Symptoms, Pictures

  https://www.medicinenet.com/hives/article.htm

  Physical urticaria (for example, heat hives) is a type of chronic urticaria produced by physical stimuli. Common environmental provocations such as sunlight (solar urticaria), water, cold, heat, exercise, and pressure occasionally induce hives. […] Another common form of physically induced hives is called cholinergic urticaria. This produces hundreds of small, itchy bumps. These occur within 15 minutes of exercise or physical exertion and are usually gone before a doctor can examine them. This form of hives happens more often in young people.

• #1 Hives (urticaria): Causes, pictures, and treatments

  https://www.medicalnewstoday.com/articles/157260

  A physical trigger other than an allergen can cause hives. Here are some possible triggers: sunlight exposure, scratching or rubbing the skin, pressure, from a tight belt, for example, extreme temperatures or changes in temperature, a high body temperature, due to sweating, exercise, anxiety, or a hot shower, adrenalin, which the body releases during exercise and exposure to heat or stress, UV light from a tanning bed, water on the skin, in rare cases, vibration, in rare cases. […] Some examples of health conditions that can cause hives include: viral infections, such as flu, the common cold, glandular fever, or hepatitis B, bacterial infections, such as some urinary tract infections and strep throat, intestinal parasites, such as Giardia lamblia, autoimmune hypothyroidism, autoimmune conditions, such as rheumatoid arthritis, systemic lupus erythematosus, Sjgrens disease, celiac disease, and type 1 diabetes, any other condition that causes inflammation of blood vessels.

• #1 Hives (Urticaria) and Angioedema Overview

  https://www.aaaai.org/tools-for-the-public/conditions-library/allergies/hives-(urticaria)-and-angioedema-overview

  Hives or welts, also known as urticaria, are itchy, raised, reddish areas on the skin. […] Understanding the underlying mechanism of swelling or the specific disease is critical in determining the best treatment. […] When hives last longer than 6 weeks, we change the name to chronic urticaria. […] The most common form of the inducible urticarias is called dermatographic urticaria. […] Usually the cause of chronic spontaneous urticaria is not fully known but is not usually caused by allergies. This is a constant finding of medical authorities and researchers around the world. […] Sometimes chronic hives may be autoimmune in nature, or related to an autoimmune condition including autoimmune thyroid disease, rheumatoid arthritis or systemic lupus erythematousus. […] This may suggest a special situation requiring additional evaluation.

• #1 The Five Most Common Causes of Hives – Trillium Creek Dermatology

  https://www.trilliumcreekohio.com/the-five-most-common-causes-of-hives/

  Approximately 20% of the population will suffer from hives at some point in their lifetime. Medically referred to as urticaria, this uncomfortable skin rash may last a few minutes to several days. […] Allergies are the most frequent cause of hives, but various other things may induce the condition. […] The most frequent reason for a hive breakout is an allergic response. […] Hives often occur due to food allergies, such as an intolerance to citrus fruits, eggs, shrimp, milk, and peanuts. […] Stress is a leading cause of hives. […] Emotional stress may trigger chemical and hormonal imbalances that contribute to the development of hives or “stress rashes.” […] Several illnesses such as the flu or the common cold can cause hives, bacteria, and fungal diseases. […] Although uncommon, it is possible to suffer from hives after being exposed to the sun. […] Hives can also emerge due to cold temperatures or water exposure.

• #1 Patient education: Hives (urticaria) (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/hives-urticaria-beyond-the-basics

  Chronic hives – Chronic hives occur daily or almost daily and last longer than six weeks, sometimes for years. In most cases of chronic hives, the cause is unknown. Researchers suspect that problems in the immune system play a role. […] Hives can be a sign of several other medical or autoimmune conditions, including thyroid or liver diseases, chronic infections, or lupus. Most people with one of these conditions will have other symptoms apart from hives. […] Inducible hives – Hives can be triggered by a variety of physical factors: […] Exposure to cold – The hives often appear as the cold skin warms again. […] Changes in body temperature or sweating – These hives are often tiny and numerous and appear on reddened skin. […] Vibration – Palms may become red, swollen, and itchy after holding onto the handle of a lawnmower.

• #1 Patient education: Hives (urticaria) (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/hives-urticaria-beyond-the-basics

  HIVES OVERVIEW […] „Urticaria” is the medical term for hives. Hives develop when there is a reaction that activates immune cells in the skin called mast cells. When activated, these cells release natural chemicals. One important chemical is histamine, which causes itching, redness, and swelling of the skin in an area: a hive. […] […] Acute hives – Most cases of hives are acute and will not last beyond a few days to one week or two. Triggers of acute hives can include the following: […] Infections – Infections can cause hives in some people. In fact, viral infections cause more than 80 percent of all cases of acute hives in children. A variety of viruses can cause hives (even routine cold viruses). The hives seem to appear as the immune system begins to clear the infection, sometimes one week or more after the illness begins. The hives usually persist for one week or two and then disappear.

• #1 Hives: Causes, Risks, Prevention, and Pictures

  https://www.healthline.com/health/hives

  Its also possible to develop hives as the result of excessive exposure to hot or cold temperatures or from irritation due to excessive sweating. Because there are several potential triggers, many times the actual cause of hives cant be determined. […] The most common causes of hives are allergic reactions. These can be caused by any allergen you might be sensitive to, including: foods (such as nuts, milk, and eggs), pet dander, pollen, dust mites, insect bites or stings, medications (primarily antibiotics, cancer drugs, or ibuprofen). […] Chronic hives may also be a symptom of an underlying health problem, such as: an autoimmune disorder, celiac disease, lupus, type 1 diabetes, rheumatoid arthritis, thyroid disease. […] Both viral and bacterial infections can cause hives. Common bacterial infections causing hives include urinary tract infections and strep throat. Viruses that cause infectious mononucleosis (mono), hepatitis, and colds often cause hives.

• #1 Chronic Urticaria – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK555910/

  Infections by a variety of organisms have also been associated with CSU. These include bacteria (Helicobacter pylori, Streptococci, Staphylococci, Yersinia, Mycoplasma pneumoniae), virus (Hepatitis virus, Norovirus, Parvovirus B19), and parasites (Giardia lamblia, Entamoeba spp., Anisakis simplex). Causality remains unproven but may involve infection-mediated autoimmune response and molecular mimicry. […] Foods and additives, while implicated in acute IgE-mediated food allergy, are rarely the cause of CSU. […] Evidence for the association between malignancy and CSU is conflicting as different studies, including retrospective studies and systematic reviews, demonstrate varying results.

• #1 9 Common causes of urticaria

  https://careplusvn.com/en/9-common-causes-of-urticaria

  Viral infections such as hepatitis B and C; bacterial infections in the ears, nose, and throat; digestive organs, teeth, mouth, urinary tract, genitals, intestinal parasites (worms, flukes) or fungal infections of the skin and internal organs. […] From the bites of some insects such as mosquitoes, fleas, bees, ants, worms. […] From cosmetics, lipsticks, powders, perfumes, hair dyes, nail polishes, pedicures, soaps, etc. Food colorings and food preservatives can also cause urticaria. […] Urticaria can appear because the patient has a systemic disease such as lupus erythematosus, diabetes, hyperthyroidism, vasculitis… […] If someone in the family has had urticaria, the possibility that a family member will have the disease is not small. […] Patients with symptoms such as redness, itching, discomfort, etc. need to go to a medical facility with a specialty in Dermatology to be examined and tested to find out the direct cause of the disease.

• #1 Chronic Hives (Chronic Idiopathic Urticaria): Causes & Treatment

  https://my.clevelandclinic.org/health/diseases/22900-chronic-hives-chronic-idiopathic-urticaria

  Chronic hives are itchy, raised, red bumps or welts that appear on your skin at least twice per week. These welts, also called wheals, are chronic when they last more than six weeks. […] For most people with chronic hives, there’s no known cause. Rarely, medication allergies or food allergies cause chronic hives. The most common allergic cause is something you consume on a regular basis. Other types of allergies may also bring on chronic hives. […] Some people develop chronic hives when their body changes temperature rapidly due to heat, cold or physical activity. Pressure on your skin from tight clothing may also cause the condition. […] About 1 in 5 people who develop chronic hives also have an autoimmune disease, such as: Celiac disease, Dermatomyositis, Diabetes, Lupus, Polymyositis, Rheumatoid arthritis, Thyroid disease, Vitiligo.

• #1 Urticaria (Hives): a complete overview — DermNet

  https://dermnetnz.org/topics/urticaria-an-overview

  Chronic spontaneous urticaria has also been associated with: Chronic underlying infection, such as Helicobacter pylori (bowel parasites) […] Chronic autoimmune diseases, such as systemic lupus erythematosus, thyroid disease, coeliac disease, vitiligo, and others. […] Inducible urticaria is a response to a physical stimulus.

• #1 Chronic Urticaria – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK555910/

  Chronic spontaneous urticaria is defined as the occurrence of wheals and/or angioedema for a total duration of six weeks or more. […] This activity reviews the etiology, pathogenesis, and management of chronic spontaneous urticaria and highlights the role of the interprofessional team in improving care for patients with this condition. […] The etiology of CSU is yet to be fully established. The prevailing hypothesis is that it relates to autoimmune dysfunction involving autoantibodies targeting IgE and/or IgE receptors to activate histamine release from basophils and mast cells. Up to 40% of patients with CSU demonstrate a positive autologous serum skin test (ASST), whereby the patients serum injected into the dermis can induce urticaria. […] Further support is lent by the increased prevalence of autoimmune disorders amongst CSU patients. Of these, autoimmune hypothyroidism is the most common, observed in up to 9.8%. Other associated conditions include rheumatoid arthritis, systemic lupus erythematosus, Sjogren syndrome, celiac disease, and type-1 diabetes mellitus.

• #1 Acute and Chronic Urticaria: Evaluation and Treatment | AAFP

  https://www.aafp.org/pubs/afp/issues/2017/0601/p717.html

  In some patients, physical stimuli, including pressure, cold, heat, and the raising of the core body temperature (cholinergic urticaria), cause urticaria that tends to be chronic. Systemic disease is an uncommon cause of urticaria. Illnesses that have been associated with urticaria or angioedema include Hashimoto thyroiditis, mastocytosis, systemic lupus erythematosus, Sjgren syndrome, rheumatoid arthritis, vasculitis, celiac disease, and lymphoma. Causes of acute urticaria often can be identified during the patient history, although 80% to 90% of chronic urticaria cases are idiopathic.

• #1 Chronic Hives (Chronic Idiopathic Urticaria): Causes & Treatment

  https://my.clevelandclinic.org/health/diseases/22900-chronic-hives-chronic-idiopathic-urticaria

  Other conditions that may cause chronic hives include: Asthma, Infections like H. pylori bacterial infections and sinus infections (sinusitis), Liver disease, Lymphomas, including Hodgkin lymphoma and non-Hodgkins lymphoma, Vasculitis. […] Chronic hives are visible at least twice per week for more than six weeks. Some chronic hives last for months or years. The cause is often unknown.

• #1 Chronic Hives: Causes, Treatment, and How to Find Relief

  https://www.vucare.com/2021/10/12/chronic-hives-symptoms-causes-find-relief/

  Chronic hives, which may also be known as chronic urticaria, are similar to the hives most people are familiar with seeing appear as an allergic reaction or due to a viral infection. […] Unfortunately, the cause of chronic hives is often unknown. However, many times the causes of hives, whether acute or chronic, are the same. This includes, but is not limited to the following: […] Autoimmune conditions may be a trigger of chronic hives, with about 1 in 5 people who develop chronic hives also having an autoimmune condition like diabetes, thyroid disease, celiac disease, or vitiligo. […] Some forms of cancer may cause chronic hives, including thyroid cancer, breast cancer, lymphoma, and others. […] However, it is important to note that simply developing chronic hives does not necessarily indicate you have an underlying condition; hives can be triggered by almost anything bothering your body, including both external and internal irritants. This is why causes of chronic hives are so difficult to pinpoint; the good news is there are still options available to help treat your chronic hives, even if the cause is not immediately apparent.

• #1 Hives (urticaria): Causes, pictures, and treatments

  https://www.medicalnewstoday.com/articles/157260

  Yes, stress can cause hives in some people. The reason for this is that stress causes a release of adrenalin, which can be a trigger for hives. […] Certain autoimmune conditions can cause chronic hives. These include systemic lupus erythematosus, rheumatoid arthritis, celiac disease, Sjgrens disease, and type 1 diabetes.

• #1 Causes and Risk Factors of Urticaria (Hives)

  https://www.verywellhealth.com/causes-of-urticaria-82866

  Stress is commonly associated with the development or worsening of chronic hives. There’s a significant number of people with chronic urticaria (35% to 60%) who have a co-occurring mental health condition, including anxiety and depression. […] Physical activity can cause urticaria to appear in some people. The cause remains unknown, although it’s common for another co-occurring food allergy to be present. […] There are certain infections and diseases for which urticaria is common. This is especially true for young children in whom 80% of hives are caused by a viral infection. […] Hives are a common allergy response to foods, medication, or environmental exposure. The itchy rash and red welts also can occur with chronic autoimmune conditions, infections, and other medical causes.

• #1 Chronic hives – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/chronic-hives/symptoms-causes/syc-20352719

  Hives also called urticaria (ur-tih-KAR-e-uh) is a skin reaction that causes itchy welts. Chronic hives are welts that last for more than six weeks and return often over months or years. Often, the cause of chronic hives isn’t clear. […] The welts that come with hives are caused by the release of immune system chemicals, such as histamine, into your bloodstream. It’s often not known why chronic hives happen or why short-term hives sometimes turn into a long-term problem. […] The skin reaction may be triggered by: Heat or cold. Sunlight. Vibration, such as caused by jogging or using lawn mowers. Pressure on the skin, as from a tight waistband. Medical conditions, such as thyroid disease, infection, allergy and cancer.

• #1 CHRONIC URTICARIA

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3276885/

  In 1983, Leznoff et al, suggested an autoimmune basis for the urticaria. This was after the observation that there was an association between thyroid disease and CIU. After that in 1988 Gruber et al, detected functional anti-IgE antibodies and proposed that these could be the cause of urticarial wheals. It is now well-established that about 30-50% patients with CU have circulating functional auto antibodies against the high-affinity IgE receptor (FCeRIa) or against IgE. […] Most cases of CU are considered idiopathic. It has recently been accepted that autoimmunity plays a critical role in its pathogenesis in some of these patients. […] Urticaria has been reported to be associated with a number of infections; however, these associations are not strong and may be spurious. […] Some authors suggest that the etiology of disease for a portion of CIU patients is a pseudoallergy to food ingredients. […] Chronic autoimmune urticaria is caused by anti-FcRI and less frequently, by anti-IgE autoantibodies that lead to mast cell and basophil activation.

• #1 Hives: Causes

  https://www.aad.org/public/diseases/a-z/hives-causes

  Others get hives when they have a medical treatment like radiation therapy or a blood transfusion. […] While some people can trace hives back to a trigger like an allergic reaction, exposure to cold, or stress, the cause remains a mystery for many people. […] It’s estimated that millions of people in the United States will develop hives during their lifetime and never find the cause. Some of these people will continue to have hives for six weeks or longer. When this happens, the person has a medical condition called chronic spontaneous urticaria. […] When chronic, hives can continue to appear for months and sometimes years. During this time, the swelling, pain, and discomfort can be difficult to live with. […] Women are twice as likely as men to develop chronic spontaneous hives during their lifetime. Most women develop this condition when they are 20 to 40 years of age. […] While anyone can develop hives, you have a greater risk if you: Are a woman of African American heritage (4 to 5 times greater risk than white people), Have atopic dermatitis (eczema), Smoke cigarettes.

• #1 Causes and Risk Factors of Hives (Urticaria)

  https://www.health.com/hives-causes-and-risk-factors-6951314

  Certain medications and plant chemicals can trigger inflammatory skin reactions in some people. Your immune system reacts using mast cells, or a type of white blood cell in your skin cells and other body parts. This allergic reaction is known as direct mast cell activation, which is not IgE-mediated. […] Some people can develop hives when their skin is exposed to certain environmental or physical factors. This is called inducible urticaria, or physical urticaria, which occurs in up to 30% of adults with chronic hives. […] Research has found that some types of hives can happen in people with a genetic predisposition. Studies on identical twins and their shared urticaria (compared with fraternal twins, who don’t have identical DNA) support this theory. Other evidence suggests that certain gene variants (genetic polymorphisms) can increase someone’s susceptibility to acute urticaria triggered by NSAIDs.

• #1 Urticaria: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/762917-overview

  Urticaria (hives) results from the release of histamine, bradykinin, leukotriene C4, prostaglandin D2, and other vasoactive substances from mast cells and basophils in the dermis. […] The cause of acute generalized urticaria (hives) often is undetermined (some sources report that the cause is undetermined in more than 60% of cases). Known causes include the following: […] Chronic urticaria can be related to all of the above as well as to the following: […] The etiology of chronic urticaria is undetermined in at least 80-90% of patients. […] Urticaria pigmentosa (cutaneous mastocytosis) is a unique dermatologic disorder caused by infiltration of mast cells in the skin and has a pathology distinct from common urticaria but can present with urticarial lesions associated with blisters.

• #1 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Hives-Pathophysiology.aspx

  Urticaria or hives is commonly caused by the release of histamine and other chemical messengers in the skin surface. […] Some common causes of hives include allergies to: […] Long term urticaria may occur with autoimmune diseases such as lupus or rheumatoid arthritis. […] The reaction begins when cutaneous mast cells and basophils release histamine and other inflammatory mediators at the skin’s surface. […] Histamine triggers the dilation of the blood vessels across the skin leading to its warm and reddish appearance.

• #1 Hives – UF Health

  https://ufhealth.org/conditions-and-treatments/hives

  Often, the cause of hives is not known. […] The majority of urticaria develop as a result of allergic reactions. Occasionally, they may be associated with autoimmune diseases, infections (parasitosis), drugs, malignancy, or other causes. […] Hives develop when histamine is released into the small blood vessels (capillaries). The capillaries dilate which causes a welt, and fluid oozes into the surrounding tissue, causing swelling. Histamine also causes intense itching.

• #1 Hives: Causes, Symptoms & more – USZ

  https://www.usz.ch/en/disease/hives/

  A variety of factors can contribute to or cause hives. Therefore, the cause research is complex. […] Research into the causes of hives (urticaria) is very complex. In many cases, no specific trigger can be traced. […] Even though the development of hives is very complex, all forms have one thing in common: certain immune cells (so-called mast cells) secrete pro-inflammatory messenger substances, including predominantly histamine. […] Various factors can cause hives to break out and the typical rash to develop. […] The three main forms include: […] In spontaneous urticaria, wheals or angioedema form spontaneously, out of the blue. […] Possible triggers are: […] Pressure and temperature stimuli trigger physical urticaria. […] There are several triggers of physical hives. […] Why the mast cells in your skin release an increased amount of the messenger substance histamine has not yet been conclusively clarified.

• #1 Urticaria and Other Skin Allergy | Allergy UK | National Charity

  https://www.allergyuk.org/types-of-allergies/urticaria-hives-other-skin-allergy/

  Urticaria is also known as ‘nettle rash’ or ‘hives’. This condition consists of wheals – spots or patches of raised red or white skin – each of which usually clears away in a few hours to be replaced by other fresh wheals. Urticaria is very common and affects one in five people at some point in their lives. […] The many different clinical forms of urticaria and they can be divided according to their duration into acute (less than 6 weeks) and chronic (more than 6 weeks) and other. […] The most common form of urticaria is acute urticaria or “acute spontaneous urticaria”, which lasts a maximum of six weeks (usually a few days to three weeks) and is usually easy to treat. […] If urticarial symptoms—redness, hives, and itching—persist much longer than 6 weeks, it is called chronic spontaneous urticaria.

• #1 Hives, Urticaria, and Angioedema: Symptoms, Causes, and Treatment

  https://www.webmd.com/allergies/hives-urticaria-angioedema

  Hives are swollen, pale red bumps, patches, or welts on the skin that appear suddenly. They can happen because of allergies or other reasons. Your doctor may call them urticaria. […] Allergic reactions, chemicals in foods, insect stings, sunlight, and medicines can make your body release a chemical called histamine. Histamine sometimes makes blood plasma leak out of small blood vessels in the skin, causing hives or angioedema. […] Sometimes, doctors dont know exactly why hives have formed. […] Viral, bacterial, or fungal infections may trigger hives, and they frequently happen again. […] The most common causes are foods, medicines, latex, and infections. Insect bites or a disease may also be responsible. […] The cause is usually harder to find than in acute cases. The causes can be similar to those of acute urticaria but can also include your immune system, chronic infections, hormonal disorders, and tumors. […] Hives caused by direct physical stimulation of the skin for example, cold, heat, sunlight, vibration, pressure, sweating, and exercise. […] Hives that form after firmly stroking or scratching the skin.

• #1 Causes and Risk Factors of Urticaria (Hives)

  https://www.verywellhealth.com/causes-of-urticaria-82866

  Urticaria, or hives, is a common type of rash characterized by the formation of raised, red, itchy bumps on the skin. Urticaria is commonly associated with an allergy to food, medications, and other irritants. Stress, infection, autoimmune disease, and even food poisoning can lead to hives. […] Allergy is a common cause of urticaria. The red welts, itchy rash, and other symptoms are caused when the immune system responds abnormally to an otherwise harmless substance and floods the body with inflammatory chemicals including histamine. […] Hives sometimes occur when the skin rash is provoked by specific environmental or physical stimuli. Some of the causes of physical urticaria include: Water: Aquagenic urticaria is a rare form of hives caused by contact with water. Sunlight: Solar urticaria is caused by exposure to ultraviolet (UV) light. Heat rash: Sometimes called cholinergic urticaria, it is caused by sweaty or hot skin. Cold: Rarely, cold can cause hives after exposure. Friction: These dermographic urticaria are caused by friction or the firm stroking of skin. Pressure: Urticaria can occur when excessive pressure is exerted on the skin, such as when you carry a heavy bag on your shoulder. Vibration: These hives form due to vibration, including mowing the lawn or clapping.

• #1 Patient education: Hives (urticaria) (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/hives-urticaria-beyond-the-basics

  Delayed pressure – Hives on the palms or the soles of the feet can occur hours after carrying heavy objects or walking long distances. […] Exercise – Hives that appear during exercise can be a sign of a dangerous condition called exercise-induced anaphylaxis. […] There are also things that do not usually cause hives and swelling but can make them harder to control. These include over-the-counter NSAID medications used to treat pain and fever and any kind of opioid medication. […] HIVES TESTING […] Most people with hives do not need any testing. The diagnosis is usually based on their symptoms and a physical examination. However, tests may be recommended if hives do not resolve within six weeks. […] Testing – Skin testing for food and drug sensitivities may be recommended if there are concerns about allergies as a cause of symptoms. This is usually done for people with acute hives. Chronic hives are rarely caused by an allergy.

• #1 Patient education: Hives (urticaria) (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/hives-urticaria-beyond-the-basics

  Drugs – Many types of drugs can trigger hives, including antibiotics and nonsteroidal antiinflammatory drugs (NSAIDs), such as aspirin, ibuprofen, or naproxen. […] Insect stings – Stings from certain insects (bees, wasps, hornets, fire ants) can cause hives around the area of the sting. […] Food allergies – Food allergy can cause acute hives in some people. Food-associated hives typically appear within 30 minutes of eating the food. The foods most likely to cause hives in children include milk, eggs, peanuts, other nuts, soy, and wheat. The foods most likely to cause hives in adults include fish, shellfish, peanuts, and other nuts. […] Physical contact – Hives can occur after you touch certain substances if you are allergic to them. For example, children who are allergic to dogs may get hives if a dog licks them. Other things that can cause hives (if you are allergic) include plants, raw fruits and vegetables, and latex (found in balloons, latex gloves, condoms, and other common items).

• #1 What is Chronic Urticaria? – Allergy & Asthma Network

  https://allergyasthmanetwork.org/chronic-urticaria/

  Chronic urticaria is caused by a release of histamine and other mediators. When this release happens in the outer layers of the skin, it results in hives. Most of the time, it is a case of acute hives, which resolves quickly. But the hives can become chronic. […] Doctors often don’t know what causes chronic hives. For as many as 80-90% of people with chronic urticaria, the cause of symptoms is unknown. […] Autoimmune conditions such as systemic lupus erythematosus may play a role in some cases of chronic urticaria. There are also systemic diseases, such as certain types of cancer, that can cause hives. […] Physical and non-physical factors can trigger chronic urticaria. […] Sometimes there is no identifiable cause for chronic urticaria. This is known as chronic spontaneous urticaria or chronic inducible urticaria. […] About 30-40% of chronic urticaria cases are related to an autoimmune condition and can be considered autoimmune urticaria.

• #1 Hives

  https://www.seattlechildrens.org/conditions/a-z/hives/

  Viral Infection. The most common cause of hives all over the body is viral infections. Research has confirmed this. Other symptoms such as a fever, cough or diarrhea are also present. The hives may last 3 days. This is not an allergy. […] Most widespread hives are caused by a viral infection. This is not due to an allergy. Less than 10% are an allergic reaction to a food, drug, or insect bite. Often, the cause is not found. […] Over 30% of the time, the cause of hives is not found. […] Localized hives are not caused by drugs, infections or swallowed foods. These get into the bloodstream and cause widespread hives. […] Most are caused by skin contact with an irritant. Examples are plants, pollen, food or pet saliva. […] Hives from foods usually last just a short time. They often are gone in less than 6 hours.

• #1 Hives, Hives and More Hives! | Texas Children’s

  https://www.texaschildrens.org/content/wellness/hives-hives-and-more-hives

  Hives (or chronic urticaria) are often caused by allergic reactions to food or medicine but can also be caused by infections, stress or underlying health conditions. […] Most hives are caused by a viral infection. In fact, it is estimated that less than 10% are caused by allergic reactions to a food, drug or insect bite. […] Acute urticaria in a child can be caused by infections, foods, medications, insect bites or blood transfusions. […] Common causes of hives in kids: Some infections that can cause hives in children include respiratory viruses (common cold), strep throat, urinary tract infections, hepatitis, infectious mononucleosis (mono) and many other viral infections. […] Chronic hives can also be caused by thyroid disease, other endocrine problems or, very rarely in children, cancer. […] In many cases, we cannot identify the cause of chronic hives, and this is called idiopathic urticaria, or chronic autoimmune urticaria, when the immune system is suspected to be the root cause of the hives.

• #1 Urticaria (Hives) in Children | Cedars-Sinai

  https://www.cedars-sinai.org/health-library/diseases-and-conditions—pediatrics/u/urticaria-hives-in-children.html

  Hives (urticaria) are a sudden outbreak of red, itchy, and swollen areas on the skin. This condition often happens as an allergic reaction from eating certain foods or taking certain medicines. It can also be caused by many other kinds of allergens. […] However, in many cases, the cause of the hives is not known. […] Causes of hives in children can include food, medicines, and other triggers. Common causes include: Foods, such as peanuts, milk, eggs, or shellfish; Antibiotics, such as penicillin or sulfa-containing antibiotics; Anticonvulsant (antiseizure) medicines, such as phenobarbital; Aspirin; Response to an infection, commonly a virus; Bites or stings from bees or other insects. […] Other types of hives include: Chronic idiopathic hives. These are hives that come back with no known cause. This is a very common cause of hives. […] Causes of hives include food, medicines, and other triggers.

• #1 Content – Health Encyclopedia – University of Rochester Medical Center

  https://www.urmc.rochester.edu/Encyclopedia/content.aspx?ContentTypeID=90&ContentID=P01688

  Causes of urticaria in children include food, medicines, and other triggers. These causes include: […] However, the most common cause of urticaria in children is virus-induced and happens when your child is sick or shortly after an illness. These hives are not due to allergies. Other types of hives include: […] Most urticaria in children are caused by viral acute illnesses. Other causes of urticaria include food, medicines, and other triggers.

• #1 Hives / Urticaria | ColumbiaDoctors

  https://www.columbiadoctors.org/treatments-conditions/hives-urticaria

  Hives or urticaria are a type of rash consisting of itchy, swollen, red welts. […] Foods, medications, infections, exercise, scratching, alcoholic beverages, emotional stress and many other factors may worsen hives. […] The most common cause of hives is infections. Foods such as eggs, nuts and shellfish are common causes of urticaria. Medications such as aspirin and antibiotics (especially penicillin and sulfa) also are common causes of hives. […] In most cases, the cause of chronic hives will not be identified despite testing. […] Rarely, chronic urticaria has been associated with cancer. […] In some cases, the cause is clear. […] If allergy is suspected, a diary of foods eaten within a few hours before the hives started may be extremely helpful. […] It is rare for a food to cause chronic hives. The specific cause of hives is rarely identified.

• #1 Acute Urticaria: Background, Etiology, Pathophysiology

  https://emedicine.medscape.com/article/137362-overview

  A number of drugs, such as aspirin, NSAIDs, opiates, succinylcholine, and certain antibiotics can cause urticaria by a nonallergic mechanism rather than by IgE-mediated hypersensitivity. […] Urticaria has been reported with infectious diseases. Viral infections associated with acute urticaria include acute viral syndromes, hepatitis (A, B, and C), Epstein-Barr virus, and herpes simplex virus. […] Although sinusitis, cutaneous fungal infections, Helicobacter pylori infection, or other occult infections have been reported in the literature to cause urticaria, the data are not strongly supported. […] Hormonal causes via endocrine tumors or ovarian pathology are rare. Oral contraceptive use or changes in the menstrual cycle have been reported as a possible cause of urticaria: patients commonly report worsening of hives with the menstrual cycle.

• #1 Acute Urticaria: Background, Etiology, Pathophysiology

  https://emedicine.medscape.com/article/137362-overview

  In 50% of patients with acute urticaria, a specific etiology can be identified. […] Brief episodes of urticaria can be associated with identifiable causes, and the method of exposure (ie, direct contact, oral or intravenous routes) is usually known. Acute urticaria is often associated with a recent infection. […] Food allergy should be considered in acute urticaria and urticaria in children. Such foods as tree nuts, peanuts, eggs, shellfish, and tomatoes should be considered (the involvement of food additives or preservatives is controversial). […] Theoretically, almost any drug can cause an allergic reaction; thus, allergic reactions to a wide variety of drugs can occur. Antibiotics, such as penicillin, have been implicated most frequently. […] Urticaria may be caused by other immediate hypersensitivity allergic reactions to an ingested, inhaled, or percutaneously inoculated substance (eg, latex, stinging insects, occupational exposures).

• #1 Hives (Urticaria) | Causes, Symptoms & Treatment

  https://acaai.org/allergies/allergic-conditions/skin-allergy/hives/

  Hives usually are caused by other things besides infection, although it could be from a virus. It could be from an allergen, or some sort of an allergy that you have. It could be from a hormonal change. And it even could be emotional in some situations. […] Researchers have identified many – but not all – of the factors that can cause hives. These include food and other substances you take, such as medications. Some people develop hives just by touching certain items. Some illnesses also cause hives. Here are a few of the most common causes: […] Chronic hives may also be associated with thyroid disease, other hormonal problems or, in very rare instances, cancer. Even this condition usually dissipates over time.

• #1 Hives: Causes, Symptoms & more – USZ

  https://www.usz.ch/en/disease/hives/

  The following factors can also trigger hives: […] If certain substances in food are suspected of causing the hives, it may be useful to follow a diet of abstinence. […] Often, several factors are responsible for the onset of hives. Sometimes the cause cannot be found out despite elaborate tests.

• #1 Patient education: Hives (urticaria) (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/hives-urticaria-beyond-the-basics

  Blood tests are sometimes done if hives continue for six weeks or longer. Blood tests can tell if there are signs of underlying diseases, such as thyroid problems or an autoimmune disease. […] Skin biopsy – A skin biopsy (when a small sample of skin is removed) may help identify uncommon causes of hives. A skin biopsy may be recommended for people who have chronic hives along with other symptoms, such as persistent fever, painful hives, individual hives that last for days at a time, or hives associated with bruising of the skin. […] HIVES TREATMENT […] Hives are treated with a combination of avoiding things that cause or worsen the hives, plus the use of medications. […] Avoiding triggers – The first treatment for hives is to figure out what is triggering your hives and then avoid that trigger.

• #2 Urticaria: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/762917-overview

  Urticaria (hives) results from the release of histamine, bradykinin, leukotriene C4, prostaglandin D2, and other vasoactive substances from mast cells and basophils in the dermis. […] The cause of acute generalized urticaria (hives) often is undetermined (some sources report that the cause is undetermined in more than 60% of cases). Known causes include the following: […] Chronic urticaria can be related to all of the above as well as to the following: […] The etiology of chronic urticaria is undetermined in at least 80-90% of patients. […] Urticaria pigmentosa (cutaneous mastocytosis) is a unique dermatologic disorder caused by infiltration of mast cells in the skin and has a pathology distinct from common urticaria but can present with urticarial lesions associated with blisters.

• #2 10 ways to get relief from chronic hives

  https://www.aad.org/public/diseases/a-z/hives-chronic-relief

  Hives are itchy welts on the skin. They can be caused by: An allergic reaction […] A medical condition, such as an infection or autoimmune disease. While medications and medical conditions can cause hives, there are many other causes, including foods, insect bites, and pressure on the skin. […] About 50% of people who have chronic hives never find out what’s causing their flare-ups. Even when the cause remains unknown, treatment can clear your skin and keep it clear.

• #2 The Five Most Common Causes of Hives – Trillium Creek Dermatology

  https://www.trilliumcreekohio.com/the-five-most-common-causes-of-hives/

  Approximately 20% of the population will suffer from hives at some point in their lifetime. Medically referred to as urticaria, this uncomfortable skin rash may last a few minutes to several days. […] Allergies are the most frequent cause of hives, but various other things may induce the condition. […] The most frequent reason for a hive breakout is an allergic response. […] Hives often occur due to food allergies, such as an intolerance to citrus fruits, eggs, shrimp, milk, and peanuts. […] Stress is a leading cause of hives. […] Emotional stress may trigger chemical and hormonal imbalances that contribute to the development of hives or “stress rashes.” […] Several illnesses such as the flu or the common cold can cause hives, bacteria, and fungal diseases. […] Although uncommon, it is possible to suffer from hives after being exposed to the sun. […] Hives can also emerge due to cold temperatures or water exposure.

• #2 Hives: Causes, Risks, Prevention, and Pictures

  https://www.healthline.com/health/hives

  Hives typically occur as an allergic response to something in your environment or something you ate. But they may sometimes happen because of an underlying health issue. […] Hives are usually caused by an allergic reaction to something that you have encountered or swallowed. When you have an allergic reaction, your body begins to release histamines into your blood. Histamines are chemicals your body produces in an attempt to defend itself against infection and other outside intruders. […] In terms of allergens, hives can be caused by factors such as pollen, medications, food, animal dander, and insect bites. […] Hives might also be caused by circumstances besides allergies. Its not uncommon for people to experience hives as the result of stress, tight clothes, exercise, illnesses, or infections.

• #2 Hives | Children’s Hospital of Philadelphia

  https://www.chop.edu/conditions-diseases/hives

  Hives appear when blood plasma leaks out of small blood vessels in the skin. This leakage occurs when the body releases histamine, a chemical that defends against harmful substances. […] Illnesses and infections are among the most common cause of hives in children. Common infections that may cause hives include colds and some bacterial or fungal infections. Illnesses such as vasculitis, lupus and thyroid disease, can also cause hives. […] Almost any prescription or over-the-counter medication can cause hives. Medications often responsible for producing hives are: penicillin, sulfa drugs, aspirin and ibuprofen. In addition, antacids, vitamins, eye and ear drops, laxatives or any other non-prescription item can cause hives. […] Dust, animals, pollen and molds can also cause hives. Coming into contact with detergents, fabric softeners, hair sprays and latex can cause hives in people who are allergic or sensitive to those substances. […] Insect bites and stings can cause hives. […] Some affected individuals can develop a lung obstruction and/or lose consciousness from hives that occur during exercise. Such a severe reaction is called exercise-induced anaphylaxis. If this occurs, call 911 immediately.

• #2 5 Common Causes of Hives: Advanced Allergy and Asthma: Allergists

  https://www.allergyasthma.clinic/blog/5-common-causes-of-hives

  An estimated 20% of people will experience hives at some point in their lives. This skin rash medically known as urticaria can last for minutes, hours, or days, even becoming a chronic condition that lasts for months or years. […] At Advanced Allergy Asthma in Ogden, Utah, our experienced allergists are experts in pinpointing the cause of hives and preventing them from occurring. In this blog, they share five of the most common causes of hives. […] Unlike a food intolerance which causes digestive upset, a food allergy causes an immune response, like hives, wheezing, and tingling or itching in the mouth. In severe cases, food allergies can also trigger life-threatening symptoms. […] Sometimes, your body can also overreact to airborne allergens, like pollen, mold spores, and pet dander. While most people associate these allergy triggers with respiratory symptoms and asthma, they can also cause a flood of histamines in your system, leading to hives and swelling in your skin.

• #2 Patient education: Hives (urticaria) (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/hives-urticaria-beyond-the-basics

  Drugs – Many types of drugs can trigger hives, including antibiotics and nonsteroidal antiinflammatory drugs (NSAIDs), such as aspirin, ibuprofen, or naproxen. […] Insect stings – Stings from certain insects (bees, wasps, hornets, fire ants) can cause hives around the area of the sting. […] Food allergies – Food allergy can cause acute hives in some people. Food-associated hives typically appear within 30 minutes of eating the food. The foods most likely to cause hives in children include milk, eggs, peanuts, other nuts, soy, and wheat. The foods most likely to cause hives in adults include fish, shellfish, peanuts, and other nuts. […] Physical contact – Hives can occur after you touch certain substances if you are allergic to them. For example, children who are allergic to dogs may get hives if a dog licks them. Other things that can cause hives (if you are allergic) include plants, raw fruits and vegetables, and latex (found in balloons, latex gloves, condoms, and other common items).

• #2 Hives (urticaria) – treatment, causes and symptoms | healthdirect

  https://www.healthdirect.gov.au/hives

  Hives, also known as 'urticaria’ or 'nettle rash’, is a skin rash that can occur for a range of reasons, including allergies, medicines or infections. […] A hives rash is caused when your body produces a substance called histamine. This is a protein released by the body in response to a perceived threat (trigger). […] In most cases, it is not known what triggers this reaction. Sometimes, urticaria can occur in response to: an infection, conditions that affect your immune system, allergies to insect stings or bites, animals, plants or foods, dye injected during a radiological test (for example, a CT scan). […] Other triggers may include: cold air or water, heat or sunlight, vibration, scratching, sweating, certain foods and drinks, such as spicy food, alcohol or coffee. […] In children, hives can be caused by a viral infection. This is why they sometimes go together with a cold or diarrhoea. […] Hives that lasts for days at a time are almost never due to an allergy, apart from some cases of medicine allergy. […] Stress rarely causes hives, but stress can make the symptoms worse.

• #2 Causes and Risk Factors of Hives (Urticaria)

  https://www.health.com/hives-causes-and-risk-factors-6951314

  Certain medications and plant chemicals can trigger inflammatory skin reactions in some people. Your immune system reacts using mast cells, or a type of white blood cell in your skin cells and other body parts. This allergic reaction is known as direct mast cell activation, which is not IgE-mediated. […] Some people can develop hives when their skin is exposed to certain environmental or physical factors. This is called inducible urticaria, or physical urticaria, which occurs in up to 30% of adults with chronic hives. […] Research has found that some types of hives can happen in people with a genetic predisposition. Studies on identical twins and their shared urticaria (compared with fraternal twins, who don’t have identical DNA) support this theory. Other evidence suggests that certain gene variants (genetic polymorphisms) can increase someone’s susceptibility to acute urticaria triggered by NSAIDs.

• #2 Chronic hives – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/chronic-hives/symptoms-causes/syc-20352719

  Hives also called urticaria (ur-tih-KAR-e-uh) is a skin reaction that causes itchy welts. Chronic hives are welts that last for more than six weeks and return often over months or years. Often, the cause of chronic hives isn’t clear. […] The welts that come with hives are caused by the release of immune system chemicals, such as histamine, into your bloodstream. It’s often not known why chronic hives happen or why short-term hives sometimes turn into a long-term problem. […] The skin reaction may be triggered by: Heat or cold. Sunlight. Vibration, such as caused by jogging or using lawn mowers. Pressure on the skin, as from a tight waistband. Medical conditions, such as thyroid disease, infection, allergy and cancer.

• #2 Chronic Hives (Chronic Idiopathic Urticaria): Causes & Treatment

  https://my.clevelandclinic.org/health/diseases/22900-chronic-hives-chronic-idiopathic-urticaria

  Chronic hives are itchy, raised, red bumps or welts that appear on your skin at least twice per week. These welts, also called wheals, are chronic when they last more than six weeks. […] For most people with chronic hives, there’s no known cause. Rarely, medication allergies or food allergies cause chronic hives. The most common allergic cause is something you consume on a regular basis. Other types of allergies may also bring on chronic hives. […] Some people develop chronic hives when their body changes temperature rapidly due to heat, cold or physical activity. Pressure on your skin from tight clothing may also cause the condition. […] About 1 in 5 people who develop chronic hives also have an autoimmune disease, such as: Celiac disease, Dermatomyositis, Diabetes, Lupus, Polymyositis, Rheumatoid arthritis, Thyroid disease, Vitiligo.

• #2 Causes and Risk Factors of Urticaria (Hives)

  https://www.verywellhealth.com/causes-of-urticaria-82866

  Urticaria, or hives, is a common type of rash characterized by the formation of raised, red, itchy bumps on the skin. Urticaria is commonly associated with an allergy to food, medications, and other irritants. Stress, infection, autoimmune disease, and even food poisoning can lead to hives. […] Allergy is a common cause of urticaria. The red welts, itchy rash, and other symptoms are caused when the immune system responds abnormally to an otherwise harmless substance and floods the body with inflammatory chemicals including histamine. […] Hives sometimes occur when the skin rash is provoked by specific environmental or physical stimuli. Some of the causes of physical urticaria include: Water: Aquagenic urticaria is a rare form of hives caused by contact with water. Sunlight: Solar urticaria is caused by exposure to ultraviolet (UV) light. Heat rash: Sometimes called cholinergic urticaria, it is caused by sweaty or hot skin. Cold: Rarely, cold can cause hives after exposure. Friction: These dermographic urticaria are caused by friction or the firm stroking of skin. Pressure: Urticaria can occur when excessive pressure is exerted on the skin, such as when you carry a heavy bag on your shoulder. Vibration: These hives form due to vibration, including mowing the lawn or clapping.

• #2 Hives (Urticaria) Causes, Fast Treatment, Symptoms, Pictures

  https://www.medicinenet.com/hives/article.htm

  Physical urticaria (for example, heat hives) is a type of chronic urticaria produced by physical stimuli. Common environmental provocations such as sunlight (solar urticaria), water, cold, heat, exercise, and pressure occasionally induce hives. […] Another common form of physically induced hives is called cholinergic urticaria. This produces hundreds of small, itchy bumps. These occur within 15 minutes of exercise or physical exertion and are usually gone before a doctor can examine them. This form of hives happens more often in young people.

• #2 Hives Information | Mount Sinai – New York

  https://www.mountsinai.org/health-library/diseases-conditions/hives

  Hives are raised, often itchy, red bumps (welts) on the surface of the skin. They can be an allergic reaction to food or medicine. They can also appear without cause. […] When you have an allergic reaction to a substance, your body releases histamine and other chemicals into the blood. This causes itching, swelling, and other symptoms. Hives are a common reaction. People with other allergies, such as hay fever, often get hives. […] Many substances can trigger hives, including: Animal dander (especially cats), Insect bites, Medicines, Pollen, Shellfish, fish, nuts, eggs, milk, and other foods. […] Hives may also develop as a result of: Emotional stress, Extreme cold or sun exposure, Excessive perspiration, Illness, including lupus, other autoimmune diseases, and leukemia, Infections such as mononucleosis, Exercise, Exposure to water. […] Often, the cause of hives is not known.

• #2 Hives

  https://www.seattlechildrens.org/conditions/a-z/hives/

  Viral Infection. The most common cause of hives all over the body is viral infections. Research has confirmed this. Other symptoms such as a fever, cough or diarrhea are also present. The hives may last 3 days. This is not an allergy. […] Most widespread hives are caused by a viral infection. This is not due to an allergy. Less than 10% are an allergic reaction to a food, drug, or insect bite. Often, the cause is not found. […] Over 30% of the time, the cause of hives is not found. […] Localized hives are not caused by drugs, infections or swallowed foods. These get into the bloodstream and cause widespread hives. […] Most are caused by skin contact with an irritant. Examples are plants, pollen, food or pet saliva. […] Hives from foods usually last just a short time. They often are gone in less than 6 hours.

• #2 Acute and Chronic Urticaria: Evaluation and Treatment | AAFP

  https://www.aafp.org/pubs/afp/issues/2017/0601/p717.html

  Urticaria and angioedema have similar underlying pathophysiologic mechanisms: histamine and other mediators released from mast cells and basophils. If the release occurs in the dermis, it results in urticaria, whereas if the release occurs in the deeper dermis and subcutaneous tissues, it results in angioedema. Immunoglobulin E (IgE) often mediates this release, but non-IgE and nonimmunologic mast cell activation also can occur. Proteases from aeroallergens and activation of the complement system have been proposed as examples of non-IgE triggers. […] There are a number of identified causes of urticaria. Common causes include allergens, food pseudoallergens (foods that contain histamine or salicylates, or cause the release of histamine directly), insect envenomation, medications, and infections. Infections are the most common cause of urticaria in children. The infectious agents commonly associated with urticaria include various viruses (e.g., rhinovirus, rotavirus, Epstein-Barr, hepatitis A, hepatitis B, hepatitis C, herpes simplex, human immunodeficiency virus), bacteria (e.g., urinary tract infections, streptococcus, mycoplasma, Helicobacter pylori), and parasites. Medications, notably beta-lactam antibiotics, typically cause urticaria via allergic reactions, although some medications (e.g., aspirin, nonsteroidal anti-inflammatory drugs [NSAIDs], vancomycin, opiates) can also trigger urticaria through direct mast cell degranulation.

• #2 Chronic Urticaria – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK555910/

  Infections by a variety of organisms have also been associated with CSU. These include bacteria (Helicobacter pylori, Streptococci, Staphylococci, Yersinia, Mycoplasma pneumoniae), virus (Hepatitis virus, Norovirus, Parvovirus B19), and parasites (Giardia lamblia, Entamoeba spp., Anisakis simplex). Causality remains unproven but may involve infection-mediated autoimmune response and molecular mimicry. […] Foods and additives, while implicated in acute IgE-mediated food allergy, are rarely the cause of CSU. […] Evidence for the association between malignancy and CSU is conflicting as different studies, including retrospective studies and systematic reviews, demonstrate varying results.

• #2 9 Common causes of urticaria

  https://careplusvn.com/en/9-common-causes-of-urticaria

  Viral infections such as hepatitis B and C; bacterial infections in the ears, nose, and throat; digestive organs, teeth, mouth, urinary tract, genitals, intestinal parasites (worms, flukes) or fungal infections of the skin and internal organs. […] From the bites of some insects such as mosquitoes, fleas, bees, ants, worms. […] From cosmetics, lipsticks, powders, perfumes, hair dyes, nail polishes, pedicures, soaps, etc. Food colorings and food preservatives can also cause urticaria. […] Urticaria can appear because the patient has a systemic disease such as lupus erythematosus, diabetes, hyperthyroidism, vasculitis… […] If someone in the family has had urticaria, the possibility that a family member will have the disease is not small. […] Patients with symptoms such as redness, itching, discomfort, etc. need to go to a medical facility with a specialty in Dermatology to be examined and tested to find out the direct cause of the disease.

• #2 Hives – Symptoms, Causes, & Treatment

  https://www.webmd.com/skin-problems-and-treatments/hives-urticaria-angioedema

  Allergic reactions, chemicals in certain foods, insect stings, sunlight, and medications can cause hives. It’s often impossible to find out exactly why hives have formed. […] The most common causes are foods, medications, and infections. Insect bites and diseases may also be responsible. […] The cause is usually harder to identify than that causing acute urticaria. For most people with chronic urticaria, the cause is impossible to find. In some cases, though, the cause may be thyroid, hepatitis, infection, or cancer. […] These hives are caused by something that stimulates the skin for example, cold, heat, sun exposure, vibration, pressure, sweating, or exercise. […] These are hives that happen when you’re stressed and your body releases inflammation-causing chemicals, triggering a skin flare-up. […] Hives happen when your body releases histamine due to various triggers, such as foods, drugs, insect bites, or infections.

• #2 What is Chronic Urticaria? – Allergy & Asthma Network

  https://allergyasthmanetwork.org/chronic-urticaria/

  Chronic urticaria is caused by a release of histamine and other mediators. When this release happens in the outer layers of the skin, it results in hives. Most of the time, it is a case of acute hives, which resolves quickly. But the hives can become chronic. […] Doctors often don’t know what causes chronic hives. For as many as 80-90% of people with chronic urticaria, the cause of symptoms is unknown. […] Autoimmune conditions such as systemic lupus erythematosus may play a role in some cases of chronic urticaria. There are also systemic diseases, such as certain types of cancer, that can cause hives. […] Physical and non-physical factors can trigger chronic urticaria. […] Sometimes there is no identifiable cause for chronic urticaria. This is known as chronic spontaneous urticaria or chronic inducible urticaria. […] About 30-40% of chronic urticaria cases are related to an autoimmune condition and can be considered autoimmune urticaria.

• #2 Hives Triggers | Chronic Urticaria

  https://resources.healthgrades.com/right-care/allergies/9-potential-causes-of-chronic-hives

  Changes in temperature trigger the welts to develop in some people who have a version of chronic hives called physical urticaria. Some are more susceptible to the cold, while heat is more of a trigger for others. And when your own temperature goes up, your sweat might even trigger the hives to develop. […] Autoimmune thyroid disease has been linked to some cases of chronic hives. Scientists are still researching the possible mechanism, and there are lots of theories under review. But if you have chronic hives with no other known cause, it might be worth asking your allergist or dermatologist about getting tested for thyroid disease. It’s possible you could have the elevated antithyroid antibodies associated with certain thyroid disorders like Hashimoto’s disease. […] Hepatitis B, which is a type of liver disease, has been associated with chronic urticaria. However, many people with hepatitis C also develop an acute form of hives, so researchers are looking at the possibility of a relationship between cases of hepatitis C and chronic hives, too.

• #2 Acute and Chronic Urticaria: Evaluation and Treatment | AAFP

  https://www.aafp.org/pubs/afp/issues/2017/0601/p717.html

  In some patients, physical stimuli, including pressure, cold, heat, and the raising of the core body temperature (cholinergic urticaria), cause urticaria that tends to be chronic. Systemic disease is an uncommon cause of urticaria. Illnesses that have been associated with urticaria or angioedema include Hashimoto thyroiditis, mastocytosis, systemic lupus erythematosus, Sjgren syndrome, rheumatoid arthritis, vasculitis, celiac disease, and lymphoma. Causes of acute urticaria often can be identified during the patient history, although 80% to 90% of chronic urticaria cases are idiopathic.

• #2 Hives Triggers | Chronic Urticaria

  https://resources.healthgrades.com/right-care/allergies/9-potential-causes-of-chronic-hives

  It’s definitely rare, but a few cases of cancer have been linked to chronic hives. And at least one large population-based study suggests people with chronic hives may be at increased risk for developing certain kinds of cancer, like cancer of the blood or lymph nodes. However, experts caution that more research is needed. […] Because it’s not annoying enough to have to cope with abdominal pain, bloating, diarrhea, and the other typical symptoms of celiac disease, you may also have to cope with an itchy red rash. Chronic hives are already associated with some other autoimmune conditions, and celiac disease is considered an “immune-mediated disease.” […] As we’ve already noted, some autoimmune diseases have been linked to some cases of chronic hives. Add lupus to the list. Again, it’s not common, but some people develop autoimmune urticaria as an early symptom of lupus.

• #2 Chronic Urticaria – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK555910/

  Chronic spontaneous urticaria is defined as the occurrence of wheals and/or angioedema for a total duration of six weeks or more. […] This activity reviews the etiology, pathogenesis, and management of chronic spontaneous urticaria and highlights the role of the interprofessional team in improving care for patients with this condition. […] The etiology of CSU is yet to be fully established. The prevailing hypothesis is that it relates to autoimmune dysfunction involving autoantibodies targeting IgE and/or IgE receptors to activate histamine release from basophils and mast cells. Up to 40% of patients with CSU demonstrate a positive autologous serum skin test (ASST), whereby the patients serum injected into the dermis can induce urticaria. […] Further support is lent by the increased prevalence of autoimmune disorders amongst CSU patients. Of these, autoimmune hypothyroidism is the most common, observed in up to 9.8%. Other associated conditions include rheumatoid arthritis, systemic lupus erythematosus, Sjogren syndrome, celiac disease, and type-1 diabetes mellitus.

• #2 Chronic Hives: Causes, Treatment, and How to Find Relief

  https://www.vucare.com/2021/10/12/chronic-hives-symptoms-causes-find-relief/

  Chronic hives, which may also be known as chronic urticaria, are similar to the hives most people are familiar with seeing appear as an allergic reaction or due to a viral infection. […] Unfortunately, the cause of chronic hives is often unknown. However, many times the causes of hives, whether acute or chronic, are the same. This includes, but is not limited to the following: […] Autoimmune conditions may be a trigger of chronic hives, with about 1 in 5 people who develop chronic hives also having an autoimmune condition like diabetes, thyroid disease, celiac disease, or vitiligo. […] Some forms of cancer may cause chronic hives, including thyroid cancer, breast cancer, lymphoma, and others. […] However, it is important to note that simply developing chronic hives does not necessarily indicate you have an underlying condition; hives can be triggered by almost anything bothering your body, including both external and internal irritants. This is why causes of chronic hives are so difficult to pinpoint; the good news is there are still options available to help treat your chronic hives, even if the cause is not immediately apparent.

• #2 Hives (Urticaria) – What Causes Hives? | familydoctor.org

  https://familydoctor.org/condition/hives-urticaria/

  Hives can appear anywhere on your body. Common symptoms include the following: […] What causes hives? Most people get hives from an allergic reaction. Your body responds to allergies by releasing chemicals into your blood. These chemicals trigger the hives. Common causes include: […] Other causes include: […] Vasculitis is a rare condition that causes painful hives. This is where your blood vessels inflame. […] It’s difficult to know what triggered hives. It may be a guess based on the various causes.

• #2 Hives / Urticaria | ColumbiaDoctors

  https://www.columbiadoctors.org/treatments-conditions/hives-urticaria

  Hives or urticaria are a type of rash consisting of itchy, swollen, red welts. […] Foods, medications, infections, exercise, scratching, alcoholic beverages, emotional stress and many other factors may worsen hives. […] The most common cause of hives is infections. Foods such as eggs, nuts and shellfish are common causes of urticaria. Medications such as aspirin and antibiotics (especially penicillin and sulfa) also are common causes of hives. […] In most cases, the cause of chronic hives will not be identified despite testing. […] Rarely, chronic urticaria has been associated with cancer. […] In some cases, the cause is clear. […] If allergy is suspected, a diary of foods eaten within a few hours before the hives started may be extremely helpful. […] It is rare for a food to cause chronic hives. The specific cause of hives is rarely identified.

• #2 Hives: Causes, Symptoms and Treatments

  https://mydoctor.kaiserpermanente.org/mas/news/hives-causes-symptoms-and-treatments-2135045

  Chronic urticaria is usually caused by an autoimmune problem with no known cause. The immune system works harder than normal and creates antibodies that start attacking allergy cells. The allergy cells release histamine, causing hives to occur spontaneously. […] When an allergist or dermatologist looks for causes of chronic urticaria, they cannot pinpoint an exact trigger in more than 90 percent of patients.

• #2 Causes and Risk Factors of Hives (Urticaria)

  https://www.health.com/hives-causes-and-risk-factors-6951314

  Hives (urticaria) causes and risk factors include allergens, exposure to insect venom, medication side effects, or certain infections. Most chronic hives, which last more than six months, are idiopathic. This means hives has no known cause. Some cases of hives can be inducible, meaning environmental factors like heat, cold, water, or sweating trigger them. […] The most common causes of hives are viral, bacterial, or parasitic infections, particularly in infants and young children. Infections can trigger your immune system into action, leading to urticaria flares. More research is needed to understand how. […] Urticaria can occur during an allergic reaction. An allergic reaction arises when your immune system misreads an allergen, usually a harmless substance, as an invader. Your immune system then attacks the allergen using an antibody (a blood protein) called immunoglobulin E (IgE). This type of allergic reaction is called an IgE-mediated response and often happens almost right away after coming into contact with an allergen.

• #2 Urticaria and Other Skin Allergy | Allergy UK | National Charity

  https://www.allergyuk.org/types-of-allergies/urticaria-hives-other-skin-allergy/

  Urticaria is also known as ‘nettle rash’ or ‘hives’. This condition consists of wheals – spots or patches of raised red or white skin – each of which usually clears away in a few hours to be replaced by other fresh wheals. Urticaria is very common and affects one in five people at some point in their lives. […] The many different clinical forms of urticaria and they can be divided according to their duration into acute (less than 6 weeks) and chronic (more than 6 weeks) and other. […] The most common form of urticaria is acute urticaria or “acute spontaneous urticaria”, which lasts a maximum of six weeks (usually a few days to three weeks) and is usually easy to treat. […] If urticarial symptoms—redness, hives, and itching—persist much longer than 6 weeks, it is called chronic spontaneous urticaria.

• #2 Hives Triggers | Chronic Urticaria

  https://resources.healthgrades.com/right-care/allergies/9-potential-causes-of-chronic-hives

  This is the catch-all category, but for good reason. Far and away, most cases of chronic hives can’t be traced back to a specific external cause. Chronic hives with no identifiable cause or trigger are called chronic spontaneous urticaria. As many as 80% of cases of chronic hives fit into this category. But researchers are working hard to determine the root of chronic hives, and today we have more treatment options than ever before, thanks to this work.

• #2 Hives (Urticaria): Causes, Symptoms, and Treatment

  https://patient.info/skin-conditions/hives-inducible-urticaria

  Hives are caused by a release of histamine; sometimes this is due to a physical stimulus. […] Hives can be triggered by a number of different physical causes. The reason why a rash appears in affected people is not clear. The physical stimulus causes a release of histamine and other chemicals, which causes the rash. […] Some known triggers include: A physical stimulus. Where this is the case the condition is called inducible urticaria. In this type of hives, a rash appears when the skin is physically stimulated (for example, by heat, cold or pressure on the skin). […] A viral infection such as the common cold or flu can trigger an urticarial rash in some people as a reaction to the virus. […] Skin contact with some substances causes a local area of contact hives in some people. For example, chemicals, latex, cosmetics, plants including pine trees, ointments, nettle stings, etc.

• #2 Content – Health Encyclopedia – University of Rochester Medical Center

  https://www.urmc.rochester.edu/Encyclopedia/content.aspx?ContentTypeID=90&ContentID=P01688

  Causes of urticaria in children include food, medicines, and other triggers. These causes include: […] However, the most common cause of urticaria in children is virus-induced and happens when your child is sick or shortly after an illness. These hives are not due to allergies. Other types of hives include: […] Most urticaria in children are caused by viral acute illnesses. Other causes of urticaria include food, medicines, and other triggers.

• #2 Hives, Hives and More Hives! | Texas Children’s

  https://www.texaschildrens.org/content/wellness/hives-hives-and-more-hives

  Hives (or chronic urticaria) are often caused by allergic reactions to food or medicine but can also be caused by infections, stress or underlying health conditions. […] Most hives are caused by a viral infection. In fact, it is estimated that less than 10% are caused by allergic reactions to a food, drug or insect bite. […] Acute urticaria in a child can be caused by infections, foods, medications, insect bites or blood transfusions. […] Common causes of hives in kids: Some infections that can cause hives in children include respiratory viruses (common cold), strep throat, urinary tract infections, hepatitis, infectious mononucleosis (mono) and many other viral infections. […] Chronic hives can also be caused by thyroid disease, other endocrine problems or, very rarely in children, cancer. […] In many cases, we cannot identify the cause of chronic hives, and this is called idiopathic urticaria, or chronic autoimmune urticaria, when the immune system is suspected to be the root cause of the hives.

• #2 Patient education: Hives (urticaria) (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/hives-urticaria-beyond-the-basics

  Antihistamines – Antihistamines are medicines that can relieve itching. Most people with hives respond to antihistamines. You may need a relatively high dose to control your symptoms. […] Oral steroids – A high dose of antihistamines is usually recommended before trying other treatments. However, oral steroids (glucocorticoids), such as prednisone, can help to relieve severe acute hives that do not get better with antihistamines. […] Other medicines – If your hives do not get better with the treatments discussed above, other treatments are available. One example is montelukast (brand name: Singulair), a medicine that helps with itching and hives in some people when used together with antihistamines. […] […] […] However, it is important to remember the following: […] Chronic hives are rarely caused by allergies and are not life threatening.

• #3 Urticaria (Hives): a complete overview — DermNet

  https://dermnetnz.org/topics/urticaria-an-overview

  What causes urticaria? Weals are due to release of chemical mediators from tissue mast cells and circulating basophils. These chemical mediators include histamine, platelet-activating factor and cytokines. The mediators activate sensory nerves and cause dilation of blood vessels and leakage of fluid into surrounding tissues. Bradykinin release causes angioedema. […] Several hypotheses have been proposed to explain urticaria. The immune, arachidonic acid and coagulation systems are involved, and genetic mutations are under investigation. […] Acute urticaria can be induced by the following factors, but the cause is not always identified. […] Chronic spontaneous urticaria is mainly idiopathic (cause unknown). An autoimmune cause is likely. About half of investigated patients carry functional IgG autoantibodies to immunoglobulin IgE or high-affinity receptor FcRI.

• #3 What Is Chronic Idiopathic Urticaria (Hives)? Symptoms, Causes, Diagnosis, Treatment, and Prevention

  https://www.everydayhealth.com/hives/what-is-chronic-idiopathic-urticaria-hives-symptoms-causes-diagnosis-treatment-and-prevention/

  Chronic urticaria are considered idiopathic when doctors are not able to identify the cause. […] Most cases of chronic hives are idiopathic, with no identifiable cause. Many researchers believe the condition is connected to an overactive immune system that attacks normal tissues of the body. […] While people often believe that hives are a response to stress, Stress can lower the threshold for developing hives, but its not the underlying cause, Aronica says. […] Some evidence suggests that people with chronic urticaria are more likely to eventually develop an autoimmune disorder, though the risk is small, says Aronica.

Zobacz więcej