Wysypka wielopostaciowa na światło – Etiologia i przyczyny

Wysypka wielopostaciowa na światło
Etiologia i przyczyny

Wysypka wielopostaciowa na światło (PMLE) jest najczęstszą immunologiczną fotodermatozą, stanowiącą około 70% zmian skórnych wywołanych promieniowaniem UV. Patogeneza PMLE opiera się na opóźnionej reakcji nadwrażliwości typu IV na endogenny antygen indukowany promieniowaniem UVA (odpowiedzialnym za 75-90% przypadków), UVB lub światłem widzialnym. Kluczowym mechanizmem jest zaburzenie immunosupresji indukowanej UV, co prowadzi do nieprawidłowej odpowiedzi immunologicznej i stanu zapalnego skóry, potwierdzonego histopatologicznie przez gęsty okołonaczyniowy naciek limfocytarny oraz zmiany w naskórku (hiperkeratoza, spongioza). Czynniki genetyczne odgrywają istotną rolę, z pozytywnym wywiadem rodzinnym u 15-46% pacjentów, a szczególnie u rdzennych Amerykanów (75%). W patogenezie uwzględnia się także wpływ hormonów, zwłaszcza estrogenu, który może hamować immunosupresję UV, co tłumaczy wyższą częstość występowania u kobiet i zmniejszenie objawów po menopauzie.

Etiologia wysypki wielopostaciowej na światło

Mechanizm immunologiczny
Rola promieniowania UV
Czynniki genetyczne
Czynniki hormonalne
Rola mikrobimu skóry i peptydów przeciwdrobnoustrojowych
Niedobór witaminy D
Efekt hartowania
Czynniki środowiskowe
Leki i substancje fotouczulające

Nowe kierunki badań nad etiologią PMLE

Podsumowanie etiologii
Kolejne rozdziały

Etiologia wysypki wielopostaciowej na światło

Wysypka wielopostaciowa na światło (Polymorphous light eruption, PMLE) jest najczęstszą formą immunologicznie mediowanej fotodermatozy. Stanowi około 70% wszystkich wywołanych słońcem zmian skórnych. Chociaż dokładna przyczyna tego schorzenia nie jest w pełni poznana, uważa się, że ma ona charakter wieloczynnikowy.¹²³

Mechanizm immunologiczny

Najbardziej uznana teoria sugeruje, że PMLE jest wynikiem opóźnionej reakcji nadwrażliwości typu IV na endogenny antygen, który pojawia się po ekspozycji na promieniowanie słoneczne lub sztuczne źródła promieniowania ultrafioletowego (UV). Reakcja ta prowadzi do stanu zapalnego skóry i pojawienia się charakterystycznych zmian skórnych.¹²³

W patomechanizmie PMLE kluczową rolę odgrywa brak immunosupresji indukowanej promieniowaniem UV. W normalnych warunkach ekspozycja na promieniowanie UV powoduje uwalnianie immunosupresyjnych cytokin z keratynocytów, co zapobiega nadmiernej reakcji immunologicznej. U pacjentów z PMLE ten mechanizm immunosupresyjny jest zaburzony, co prowadzi do nieprawidłowej odpowiedzi immunologicznej i rozwoju zmian skórnych.¹²

Badania histopatologiczne wykazują obecność gęstego okołonaczyniowego nacieku limfocytarnego w górnej i środkowej warstwie skóry właściwej, co potwierdza immunologiczny charakter schorzenia. W naskórku obserwuje się hiperkeratozę i spongiozę z lub bez obecności zwyrodnienia wodniczkowego.¹

Rola promieniowania UV

Promieniowanie ultrafioletowe jest głównym czynnikiem wywołującym PMLE. Najczęściej za wystąpienie objawów odpowiada promieniowanie UVA, które wywołuje reakcję w 75-90% przypadków. U niektórych pacjentów objawy mogą być wywołane przez promieniowanie UVB lub, rzadziej, przez światło widzialne.¹²³

Promieniowanie UVA ma zdolność penetracji głębszych warstw skóry i może przenikać przez szkło, co oznacza, że pacjenci mogą doświadczać reakcji nawet będąc za szybą. Jest to istotna różnica w porównaniu z promieniowaniem UVB, które nie przenika przez szkło.¹²³

Mechanizm działania promieniowania UV w patogenezie PMLE obejmuje:¹²

Modyfikację substancji w skórze, co prowadzi do powstania autoantygenu
Przenikanie promieniowania UVA do głębszych warstw skóry, gdzie może uszkadzać komórki
Generowanie wolnych rodników i stresu oksydacyjnego
Wywoływanie nieprawidłowej odpowiedzi immunologicznej

Czynniki genetyczne

Badania wskazują na istotną rolę czynników genetycznych w rozwoju PMLE. Obserwuje się skupianie występowania PMLE w rodzinach – około 15-46% pacjentów zgłasza pozytywny wywiad rodzinny w kierunku PMLE, co sugeruje genetyczną predyspozycję.¹²³

Szczególnie wyraźny komponent genetyczny obserwuje się u rdzennych Amerykanów, którzy mają dziedziczną formę PMLE z prawdopodobnym dziedziczeniem autosomalnym dominującym. W tej populacji aż 75% pacjentów ma członka rodziny z tym schorzeniem.¹²

Badania bliźniąt wykazały, że częstość występowania PMLE wynosiła 21% u bliźniąt jednojajowych i 18% u bliźniąt dwujajowych, co dodatkowo potwierdza rolę czynników genetycznych.¹

Mimo intensywnych badań nad genami potencjalnie zaangażowanymi w patogenezę PMLE, wyniki są generalnie mało satysfakcjonujące. Jednak pewne geny związane z oczyszczaniem komórek apoptotycznych w normalnej skórze, takie jak podjednostka dopełniacza 1s, receptor zmiatający-B1 (SCARB-1), kaspaza-1 (CASP-1) i fibronektyna (FN-1)-1, mogą odgrywać rolę w patogenezie PMLE.¹²

Czynniki hormonalne

PMLE występuje znacznie częściej u kobiet niż u mężczyzn, co sugeruje udział czynników hormonalnych w patogenezie tego schorzenia. Przypuszcza się, że estrogen może odgrywać rolę w hamowaniu immunosupresji wywołanej promieniowaniem UV, co normalnie pomogłoby ograniczyć reakcje nadwrażliwości.¹²

Teoria dotycząca wpływu 17-estradiolu zakłada, że hormon ten w pewien sposób zapobiega reakcji immunosupresyjnej, co prowadzi do PMLE. Wyjaśniałoby to zwiększoną częstość występowania PMLE u dorosłych kobiet i jej tendencję do zmniejszania się po menopauzie.¹²³

Rola mikrobimu skóry i peptydów przeciwdrobnoustrojowych

Nowsze badania wskazują na potencjalną rolę mikrobimu skóry i zaburzenia równowagi elementów mikrobiologicznych w patogenezie PMLE. Promieniowanie UV może wpływać na mikrobiom skóry, prowadząc do zaburzeń, które przyczyniają się do rozwoju stanu zapalnego.¹²

Badania wykazały również dysregulację peptydów przeciwdrobnoustrojowych (AMP) w zmianach skórnych PMLE. Te mediatory, takie jak defensyny, katelicydyna, rybonukleaza 7 i psoryzyna, odgrywają rolę w odpowiedzi immunologicznej skóry na zaburzenia równowagi wywołane przez promieniowanie UV.¹²

Zaobserwowano również zwiększone poziomy IL-36 w skórze i krwi obwodowej pacjentów z PMLE, co wskazuje na aktywację lokalnej i systemowej odpowiedzi immunologicznej, podobnie jak w wielu innych zapalnych schorzeniach skóry.¹

Niedobór witaminy D

Niedobór witaminy D3 jest uważany za czynnik ryzyka zwiększający podatność na rozwój PMLE poprzez upośledzenie funkcji immunologicznych i nasilenie stanu zapalnego. Związek między statusem witaminy D a PMLE jest obszarem aktywnych badań.¹²

Efekt hartowania

Charakterystyczną cechą PMLE jest tzw. efekt hartowania, polegający na zmniejszaniu się wrażliwości na światło słoneczne wraz z powtarzającą się ekspozycją. Ten fenomen nie jest w pełni wyjaśniony i może być związany z:¹²³

Rozwojem tolerancji immunologicznej na ekspozycję słoneczną
Stopniowym opalaniem się i pogrubieniem skóry, co zapewnia dodatkową barierę przed promieniowaniem słonecznym
Zmianami w reakcji immunologicznej skóry na powtarzające się ekspozycje na promieniowanie UV

Efekt hartowania wyjaśnia, dlaczego PMLE najczęściej pojawia się po pierwszej lub drugiej ekspozycji na słońce po długim okresie braku ekspozycji, zwykle wiosną lub wczesnym latem. Wraz z postępem lata epizody stają się mniej prawdopodobne.¹²

Czynniki środowiskowe

Występowanie PMLE wykazuje zmienność geograficzną, co sugeruje wpływ czynników środowiskowych. Częstość występowania PMLE waha się od około 1% w Chinach do ponad 20% w niektórych krajach północnoeuropejskich.¹²

PMLE częściej występuje w klimacie umiarkowanym, co może być związane z charakterem ekspozycji na słońce w tych regionach – długie okresy bez intensywnego nasłonecznienia, a następnie nagła ekspozycja na słońce wiosną i latem.¹²

Na rozwój PMLE mogą wpływać również inne czynniki środowiskowe, takie jak:¹²

Intensywność promieniowania UV
Sezonowe zmiany wzorców nasłonecznienia
Niektóre badania sugerują związek z paleniem tytoniu i spożywaniem alkoholu (sześć lub więcej drinków tygodniowo)

Leki i substancje fotouczulające

Chociaż PMLE samo w sobie nie jest wywoływane przez leki, niektóre substancje mogą zwiększać wrażliwość skóry na światło (fotouczulenie) i potencjalnie nasilać objawy PMLE lub wywoływać podobne reakcje skórne.¹²

Do leków, które mogą wywoływać lub nasilać fotowrażliwość, należą:¹

Antybiotyki, takie jak tetracyklina lub sulfonamidy
Niesteroidowe leki przeciwzapalne (NLPZ), jak naproksen lub ibuprofen
Leki przeciwmalaryczne
Niektóre leki przeciwpsychotyczne i przeciwdepresyjne

Nowe kierunki badań nad etiologią PMLE

Najnowsze badania nad patogenezą PMLE koncentrują się na kilku obiecujących obszarach:¹²³

Rodzina cytokin IL-1 – badanie roli tych mediatorów zapalnych w patogenezie PMLE
Aktywacja receptorów toll-podobnych (TLR) – zaangażowanie tych receptorów w rozpoznawanie patogenów i inicjowanie odpowiedzi immunologicznej
Stres oksydacyjny i modyfikacja statusu redoks skóry – wpływ stresu oksydacyjnego na rozwój PMLE
Apoptoza i usuwanie komórek apoptotycznych – przypuszcza się, że modyfikacja białek podczas usuwania komórek apoptotycznych może prowadzić do powstawania potencjalnych autoantygentów
Częściowa niewydolność apoptozy – przyczynia się wraz z nieadekwatną immunosupresją po ekspozycji na promieniowanie UV do rozpoznawania antygenu i jego prezentacji, prowadząc do klinicznych objawów typowych dla pacjentów z PMLE

Podsumowanie etiologii

Wysypka wielopostaciowa na światło (PMLE) jest wieloczynnikowym schorzeniem, którego pełna etiologia pozostaje nie w pełni wyjaśniona. Kluczowe elementy w jej patogenezie obejmują:¹²³⁴

Opóźnioną reakcję nadwrażliwości typu IV na antygen indukowany przez promieniowanie UV
Zaburzenie immunosupresji wywołanej promieniowaniem UV
Predyspozycję genetyczną
Wpływ czynników hormonalnych, szczególnie estrogenu
Dysregulację peptydów przeciwdrobnoustrojowych i zmian w mikrobiomie skóry
Stres oksydacyjny i modyfikację statusu redoks skóry
Czynniki środowiskowe, w tym wzorce ekspozycji na słońce i szerokość geograficzną

Zrozumienie złożonej interakcji tych czynników jest kluczowe dla opracowania skutecznych strategii zapobiegania i leczenia PMLE. Dalsze badania nad podstawowymi mechanizmami patogenetycznymi tego schorzenia powinny umożliwić bardziej ukierunkowane podejście terapeutyczne.¹²

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Materiały źródłowe

#1 Polymorphic Light Eruption – StatPearls – NCBI Bookshelf
https://www.ncbi.nlm.nih.gov/books/NBK430886/
Polymorphic light eruption is the most common form of immunologically mediated photosensitivity dermatoses. […] The cause of polymorphic light eruption is unknown. It is postulated that there is a delayed hypersensitivity reaction to an endogenous antigen expressed after exposure to sunlight or artificial sources of ultraviolet (UV) radiation. […] Theories must account for increased prevalence in women and for the hardening effect of on-going exposure to ultraviolet radiation.
#1 Polymorphic Light Eruption (PMLE): Causes and Treatment
https://patient.info/doctor/polymorphic-light-eruption-pro
The cause of PMLE is likely to be multifactorial. It is thought to be caused by an immunological reaction to a compound in the spring, but the precise nature is unknown. Findings are consistent with a type IV delayed hypersensitivity reaction. […] UV exposure causes a contact hypersensitivity response – this is normally suppressed by the release of immunosuppressive cytokines from keratinocytes. It has been suggested that 17-estradiol somehow prevents this response, thus leading to PMLE. This theory would account for the increased prevalence of PMLE in adult women and its tendency to wane after the menopause.
#1
https://journals.lww.com/idoj/fulltext/2021/12020/polymorphous_light_eruption__an_indian_scenario.1.aspx
Polymorphous light eruption (PMLE) is the most common, idiopathic, acquired photodermatosis, characterized by abnormal, recurrent, and delayed reaction to sunlight. […] It is an immunologically mediated disease that occurs due to delayed hypersensitivity reactions. […] Polymorphous light eruption occurs in family members in 12-46% of PMLE patients. Familial clustering in PMLE suggests a genetic etiology. […] PMLE occurs due to the interplay of genetic and environmental factors. […] The possible mechanisms involved in pathogenesis are given in the form of a chart which incorporates various factors involved. […] The histopathology of PMLE is characterized by the presence of hyperkeratosis, spongiosis with or without the presence of liquefactive degeneration in the epidermis. Dermal changes in the upper and mid dermis include the presence of dense perivascular lymphocytic infiltrate.
#1 Polymorphic light eruption (PMLE) â DermNet
https://dermnetnz.org/topics/polymorphic-light-eruption
Polymorphic light eruption (PMLE) is a seasonal, acquired, idiopathic photodermatosis occurring in spring and early summer. […] What causes polymorphic light eruption? There is a genetic susceptibility in 15-46% of cases where a positive family history is reported. PMLE is a delayed hypersensitivity reaction in the skin to unknown endogenous cutaneous photo-induced antigens. This abnormal response to ultraviolet (UV) light means affected patients develop an inflammatory response to an endogenous photo-induced antigen. The following factors must be considered when determining pathogenesis and when implementing protective measures: It is primarily caused by either UVA (75-90%) or UVB light alone or UVA and UVB light concurrently. It is rarely caused by visible light. UVA can penetrate window glass and some sunscreens do not protect against it. Some patients have reported a response to UVC from welding arcs. […] Because PMLE is more prevalent in women than men, it is hypothesized that there is a hormonal component to its pathogenesis. Estradiol may act as an inhibitor to the UV light immunosuppression which would normally aid in reducing hypersensitivity reactions.
#1 Polymorphous Light Eruption (PMLE): Symptoms, Causes & Treatments
https://my.clevelandclinic.org/health/diseases/17888-polymorphous-light-eruption-pmle
Polymorphous light eruption (PMLE) is a common skin rash generally caused by exposure to the suns ultraviolet (UV) light. […] Experts dont know exactly what causes this rash. Its possible that UV radiation alters a compound in your skin and your immune system reacts to the new compound. […] Both ultraviolet and occasionally visible light cause PMLE. Ultraviolet light has two types: UVA and UVB. UVB can damage your skin, but UVA penetrates deeper into your skins layers. UVA causes up to 9 in 10 cases of polymorphous light eruption. […] PMLE often occurs in the spring when sunny weather returns. […] PMLE is a benign (noncancerous) condition. While the rash doesnt increase your risk of skin cancer, exposure to UV light does. The sun-protective measures you take to prevent polymorphous light eruption also lower your risk of skin cancer.
#1 Sun allergies |sun protection | Eucerin
https://int.eucerin.com/about-skin/indications/ple-sun-allergies
Sun allergies are very common, especially among young women and people with fair skin. The most common form of sun allergy is Polymorphous Light Eruption (often abbreviated to PLE). […] The causes of PLE are not fully known but research suggests that it may be inherited. When people have the underlying condition, their immune identifies and reacts against areas of skin altered by the sun producing a rash: […] UVA rays trigger 80% of cases of PLE […] UV rays especially long wavelength UVA rays (which trigger PLE in 80% of people affected) penetrate deeply into the skin where they can damage cells. […] People with PLE have an impaired cellular defense which reduces their skins ability to handle these free radicals. […] On exposure to the sun their skin responds by over activating its immune function, resulting in red and inflamed skin.
#1 Polymorphous Light Eruption: Practice Essentials, Pathophysiology, Etiology
https://emedicine.medscape.com/article/1119686-overview
Polymorphous light eruption (PMLE) is an acquired disease and is the most common of the idiopathic photodermatoses. […] The etiology of PMLE is not fully known but is likely to be multifactorial. That PMLE clusters in families suggests a genetic component. […] The UVA light spectrum is the most common causative factor in polymorphous light eruption (PMLE). Other wavelengths, including UVB or even visible light, may also induce PMLE in some individuals. […] Overall, family history is positive for PMLE in about 15-20% of patients. However, Native Americans have a hereditary form of PMLE with apparent autosomal dominant inheritance; 75% reveal disease in a family member.
#1 Polymorphic Light Eruption: What’s New in Pathogenesis and Management
https://pmc.ncbi.nlm.nih.gov/articles/PMC6139322/
Polymorphic light eruption is the commonest photosensitive disorder, characterized by an intermittent eruption of non-scarring erythematous papules, vesicles or plaques that develop within hours of ultraviolet radiation exposure of patient skin. […] The disease is dependent on genetic susceptibility, as well as environmental component, such as type of exposure. PLE appears to cluster in families: it has been estimated that the prevalence of PLE was 21 and 18% in monozygotic and dizygotic twins, respectively. […] Many genes of potential interest in the pathogenesis of PLE have been investigated with generally unrewarding results. […] It has been supposed that protein modification during apoptotic cell clearance could lead to potential auto-antigen formation. […] This partial failure of the apoptosis contributes, together with the inadequate immunosuppression after UV exposure, to the antigen recognition and presentation, leading to the clinical manifestation typical of PLE patients.
#1 Polymorphous light eruption – Wikipedia
https://en.wikipedia.org/wiki/Polymorphous_light_eruption
Polymorphous light eruption (PLE) presents with itchy red small bumps on sun-exposed skin, particularly face, neck, forearms and legs. […] The cause of PLE is not yet understood, but several factors may be involved. […] It is thought to be due to a type IV delayed-type hypersensitivity to an allergen produced in the body following sunlight exposure, in a genetically susceptible person. […] It is also thought that skin microbiome or microbial elements could be involved in pathogenesis of the disease. […] PLE can be provoked by UVA or UVB (chief cause of sunburn) rays, meaning it can be triggered even by sunlight through glass. […] Artificial UV light sources from tanning units and phototherapy treatment units can also trigger PLE. […] Oxidative stress and the modification of the redox status of the skin has been implicated in the expression of PLE.
#1 Polymorphic Light Eruption: What’s New in Pathogenesis and Management
https://pmc.ncbi.nlm.nih.gov/articles/PMC6139322/
The immunological mechanisms involved in PLE, with mediators from the innate and adaptive immune system, are very similar, either from the histological or the biochemical point of view, to the ACD ones. […] Recently, to reinforce this concept, some of the inflammatory mediators involved in ACD have been demonstrated also in PLE. […] The increase of IL-36s in skin and peripheral blood of PLE patients indicates the activation of local and systemic immune response, as found in multiple inflammatory skin conditions. […] These mediators, named as defensins, cathelicidin, ribonuclease 7 and psoriasin, in light of the imbalance induced by UVR on keratinocytes and skin microbiome, have also been investigated in PLE. […] The first line of treatment for PLE includes sun avoidance, sunscreens and topical corticosteroids.
#1 Polymorphous light eruptions – Indian Journal of Skin Allergy
https://skinallergyjournal.com/polymorphous-light-eruptions/
Certain genes in normal skin such as complement 1s subunit, scavenger receptor-B1 (SCARB-1), caspase-1 (CASP-1) and fibronectin (FN-1)-1 are associated with apoptotic cell clearance. […] A deficiency of Vitamin D3 is considered a risk factor to increase disease susceptibility by impairing immune function and increasing inflammation. […] The newer concepts in the immunopathogenesis of PMLE include loss of UV-induced immunosuppression, involvement of the IL-1 family of cytokines, activation of toll-like receptors, and dysregulation in the levels of antimicrobial peptides.
#1 Mayo Clinic Health Library – Polymorphous light eruption | Swiss Medical Network
https://www.swissmedical.net/en/healtcare-library/con-20257399
Polymorphous light eruption is a rash caused by sun exposure in people who are sensitive to sunlight. […] The exact cause of polymorphous light eruption isn’t understood. The rash appears in people who have developed sensitivity to sunlight, especially ultraviolet (UV) radiation from the sun or other sources, such as tanning beds. This is called photosensitivity. It leads to immune system activity that causes a rash. […] With polymorphous light eruption, sensitivity to sunlight lessens with repeated exposure. Features of polymorphous light eruption are somewhat predictable: An episode is most likely to occur after the first one or two times of sun exposure after a long period of no exposure, such as in spring or early summer. Episodes are less likely to happen as the summer progresses. After the first episode, it’s likely to happen each year. Some people gradually become less sensitive over several years and eventually no longer experience the yearly rash.
#1 Polymorphous light eruption – UpToDate
https://www.uptodate.com/contents/polymorphous-light-eruption
Polymorphous light eruption (PMLE) is the most common idiopathic photodermatosis; it is sometimes called „sun poisoning” or „sun allergy.” PMLE usually presents as a pruritic rash in sun-exposed areas hours to days after ultraviolet (UV) light exposure and persists for several days before subsiding. […] PMLE occurs more frequently in temperate areas. Several studies have indicated that the prevalence of PMLE is directly related to latitude, ranging from approximately 1 percent in China to over 20 percent in some northern European countries. However, within Europe, a latitude gradient has not been shown to occur.
#1 Polymorphous light eruption
https://sales-demo.adam.com/content.aspx?productid=141&isarticlelink=false&pid=1&gid=001477
Polymorphous light eruption (PMLE) is a common skin reaction in people who are sensitive to sunlight (ultraviolet light). […] The exact cause of PMLE is unknown. However, it may be genetic. Health care providers think it is a type of delayed allergic reaction. It is common among young women who live in moderate (temperate) climates.
#1 What Is Polymorphous Light Eruption – Klarity Health Library
https://my.klarity.health/what-is-polymorphous-light-eruption/
Polymorphous light eruption (PMLE) is a skin condition that occurs when your skin is exposed to the sun, a rash would appear on that part of the skin. […] The primary cause of Polymorphous Light Eruption (PMLE) is believed to be an abnormal immune system response to ultraviolet (UV) radiation. […] The immune system normally protects the body from harmful invaders, but in PMLE, it appears to misinterpret sunlight as a threat, leading to an inflammatory response in the skin. […] There is evidence to suggest a genetic predisposition to PMLE. […] The seasonal occurrence of PMLE, often in the spring or early summer, points to a connection with changing sunlight patterns. […] The intensity of ultraviolet radiation plays a crucial role in triggering PMLE. […] There is some evidence to suggest that hormonal changes may influence the development of PMLE as it is more common for women to have PMLE than men. […] Certain medications and chemicals can increase the skin’s sensitivity to sunlight, potentially exacerbating PMLE symptoms. […] Conditions or treatments that modulate the immune system, such as autoimmune diseases or immunosuppressive therapies, may impact the likelihood of developing PMLE.
#1
https://balmonds.com/blogs/polymorphic-light-eruption-pmle/what-drugs-can-cause-polymorphic-light-eruption
Polymorphic light eruption (PMLE) is a complicated condition, characterised by an abnormal sensitivity to sunlight. Its not completely understood how people develop PMLE, but there seems to be a combination of factors involved. […] PMLE has been shown to run in families, which means that a predisposition towards sun sensitivity is part of what can add up to an outbreak of itchy, spotty or blistered rashes when skin is exposed to sunlight. […] However, these arent the same as PMLE; polymorphic light eruption is a specific kind of light sensitivity, one that is all about an extra sensitivity to sunlight that some people are born with, and which is exacerbated by circumstance and environment. […] PMLE isnt itself caused by medication, but some medications can cause a similar rash.
#1 Polymorphous Light Eruption: Symptoms, Causes, Treatment | Qwark
https://qwarkhealth.com/conditions/polymorphous-light-eruption
Polymorphous Light Eruption (PMLE) is a skin condition that occurs due to sun exposure. […] PMLE is triggered by sun exposure because of the UVA and UVB rays that can penetrate the skin deep enough to affect the immune system, which triggers an inflammatory response to sunlight. This abnormal immune response can cause skin irritation and can escalate to an inflammatory eruption like PMLE. […] PMLE is mostly prevalent in individuals of certain races (like North American Indians and Mediterranean peoples), which has led researchers to hypothesize that there may be a genetic predisposition to developing PMLE. Strong evidence for a genetic influence on PMLE development has come from family studies that demonstrate that PMLE tends to run in families. […] Yes, there are certain medications that can trigger PMLE or worsen its symptoms. Some of these medications are antibiotics like tetracycline or sulfonamide, non-steroidal anti-inflammatory drugs (NSAIDs) like naproxen or ibuprofen, etc.
#1 Polymorphic Light Eruption: What’s New in Pathogenesis and Management
https://pmc.ncbi.nlm.nih.gov/articles/PMC6139322/
New generation broad-spectrum sunscreens, with high sun protection factor for UVB, together with longer wavelength UVA protection, have been reported to confer total or partial protection in up to 90% of PLE patients. […] The mechanisms by which phototherapy induces photoprotection are not fully understood. […] However, in the last years many advances have been performed. […] The choice of the appropriate PLE treatment requires a good knowledge of the individual clinical course of the disease together with the possibility of performing phototest. […] The deeper study of the underlying pathogenetic mechanisms of the disorder will permit a more targeted treatment approach.
#2 Recognizing and preventing sun allergies – Harvard Health
https://www.health.harvard.edu/blog/recognizing-and-preventing-sun-allergies-202207052772
No one is truly allergic to the sun, but some people are quite sensitive to different types of sun rays and may develop mild to serious reactions after spending time in the sun. […] Polymorphous light eruption (PMLE), an autoimmune condition in the skin that occurs after sun exposure, is one of the most common. […] People who have PMLE have immune cells that are triggered by sun rays, which attack their skin, and they develop a skin reaction to the sun’s the ultraviolet (UV) rays. […] PMLE represents 70% of all sun-induced skin eruptions. […] PMLE may be an inherited condition. […] PMLE is more common in young women who live in temperate climates. […] Medications that reduce the immune response, such as azathioprine, are options for treating PMLE, since it is an autoimmune condition (the body is attacking it is own healthy cells). […] Oral Polypodium leucotomos extract, a natural substance derived from tropical fern leaves, may work as a potent antioxidant, and has anti-inflammatory properties that are beneficial in the prevention of PMLE.
#2 Polymorphic Light Eruption (PMLE): Causes and Treatment
https://patient.info/doctor/polymorphic-light-eruption-pro
The cause of PMLE is likely to be multifactorial. It is thought to be caused by an immunological reaction to a compound in the spring, but the precise nature is unknown. Findings are consistent with a type IV delayed hypersensitivity reaction. […] UV exposure causes a contact hypersensitivity response – this is normally suppressed by the release of immunosuppressive cytokines from keratinocytes. It has been suggested that 17-estradiol somehow prevents this response, thus leading to PMLE. This theory would account for the increased prevalence of PMLE in adult women and its tendency to wane after the menopause.
#2 Polymorphous light eruptions – Indian Journal of Skin Allergy
https://skinallergyjournal.com/polymorphous-light-eruptions/
Polymorphous light eruption (PMLE) is the most common, immunologically acquired photo-dermatosis due to delayed hypersensitivity reaction to sunlight. […] Genetic susceptibility and environmental exposure play an important role in the pathogenesis of PMLE. […] The exact etiopathogenesis of polymorphous light eruption (PMLE) is still not well understood, but the disease is linked to a delayed-type (type IV) hypersensitivity reaction to one or more endogenous photo-antigens. […] Dysregulation of AMPs is found in skin lesions of PMLE, which triggers the release of IL-31 from keratinocytes and is an important cytokine in the pathogenesis of pruritic lesions in these patients. […] In PMLE, failure of this UV-induced immunosuppression leads to reduced production of neutrophil-derived TNF-, IL-4, and IL-10, failure of Langerhans cell migration, and lack of neutrophil infiltration.
#2 Polymorphous Light Eruption (PMLE): Symptoms, Causes & Treatments
https://my.clevelandclinic.org/health/diseases/17888-polymorphous-light-eruption-pmle
Polymorphous light eruption (PMLE) is a common skin rash generally caused by exposure to the suns ultraviolet (UV) light. […] Experts dont know exactly what causes this rash. Its possible that UV radiation alters a compound in your skin and your immune system reacts to the new compound. […] Both ultraviolet and occasionally visible light cause PMLE. Ultraviolet light has two types: UVA and UVB. UVB can damage your skin, but UVA penetrates deeper into your skins layers. UVA causes up to 9 in 10 cases of polymorphous light eruption. […] PMLE often occurs in the spring when sunny weather returns. […] PMLE is a benign (noncancerous) condition. While the rash doesnt increase your risk of skin cancer, exposure to UV light does. The sun-protective measures you take to prevent polymorphous light eruption also lower your risk of skin cancer.
#2 Polymorphous light eruption – Wikipedia
https://en.wikipedia.org/wiki/Polymorphous_light_eruption
Polymorphous light eruption (PLE) presents with itchy red small bumps on sun-exposed skin, particularly face, neck, forearms and legs. […] The cause of PLE is not yet understood, but several factors may be involved. […] It is thought to be due to a type IV delayed-type hypersensitivity to an allergen produced in the body following sunlight exposure, in a genetically susceptible person. […] It is also thought that skin microbiome or microbial elements could be involved in pathogenesis of the disease. […] PLE can be provoked by UVA or UVB (chief cause of sunburn) rays, meaning it can be triggered even by sunlight through glass. […] Artificial UV light sources from tanning units and phototherapy treatment units can also trigger PLE. […] Oxidative stress and the modification of the redox status of the skin has been implicated in the expression of PLE.
#2 Polymorphous Light Eruption: Symptoms, Causes, Treatment | Qwark
https://qwarkhealth.com/conditions/polymorphous-light-eruption
Polymorphous Light Eruption (PMLE) is a skin condition that occurs due to sun exposure. […] PMLE is triggered by sun exposure because of the UVA and UVB rays that can penetrate the skin deep enough to affect the immune system, which triggers an inflammatory response to sunlight. This abnormal immune response can cause skin irritation and can escalate to an inflammatory eruption like PMLE. […] PMLE is mostly prevalent in individuals of certain races (like North American Indians and Mediterranean peoples), which has led researchers to hypothesize that there may be a genetic predisposition to developing PMLE. Strong evidence for a genetic influence on PMLE development has come from family studies that demonstrate that PMLE tends to run in families. […] Yes, there are certain medications that can trigger PMLE or worsen its symptoms. Some of these medications are antibiotics like tetracycline or sulfonamide, non-steroidal anti-inflammatory drugs (NSAIDs) like naproxen or ibuprofen, etc.
#2 Polymorphous Light Eruption: Practice Essentials, Pathophysiology, Etiology
https://emedicine.medscape.com/article/1119686-overview
Polymorphous light eruption (PMLE) is an acquired disease and is the most common of the idiopathic photodermatoses. […] The etiology of PMLE is not fully known but is likely to be multifactorial. That PMLE clusters in families suggests a genetic component. […] The UVA light spectrum is the most common causative factor in polymorphous light eruption (PMLE). Other wavelengths, including UVB or even visible light, may also induce PMLE in some individuals. […] Overall, family history is positive for PMLE in about 15-20% of patients. However, Native Americans have a hereditary form of PMLE with apparent autosomal dominant inheritance; 75% reveal disease in a family member.
#2 Polymorphous Light Eruption – UF Health
https://ufhealth.org/conditions-and-treatments/polymorphous-light-eruption
Polymorphous light eruption (PMLE) is a common skin reaction in people who are sensitive to sunlight (ultraviolet light). […] The exact cause of PMLE is unknown. However, it may be genetic. Health care providers think it is a type of delayed allergic reaction. It is common among young women who live in moderate (temperate) climates. […] The cause of polymorphous light eruption is unknown. It usually appears 1 to 2 days following exposure to sunlight and may last up to one week. It is more common during adolescence and young adulthood, and occurs more frequently in females. It may be an inherited disease in certain Native American groups.
#2 Polymorphous light eruptions – Indian Journal of Skin Allergy
https://skinallergyjournal.com/polymorphous-light-eruptions/
Certain genes in normal skin such as complement 1s subunit, scavenger receptor-B1 (SCARB-1), caspase-1 (CASP-1) and fibronectin (FN-1)-1 are associated with apoptotic cell clearance. […] A deficiency of Vitamin D3 is considered a risk factor to increase disease susceptibility by impairing immune function and increasing inflammation. […] The newer concepts in the immunopathogenesis of PMLE include loss of UV-induced immunosuppression, involvement of the IL-1 family of cytokines, activation of toll-like receptors, and dysregulation in the levels of antimicrobial peptides.
#2 Polymorphous light eruption – Wikipedia
https://en.wikipedia.org/wiki/Polymorphous_light_eruption
It has been suggested that an undefined endogenous or exogenous photo-allergen may trigger a delayed immune reaction resulting in PLE. […] Half of patients have a family history of PLE, demonstrating a clear genetic influence. […] The preponderance in women with a decline in severity following menopause has been thought to be associated with oestrogen effects.
#2 Polymorphic Light Eruption: What’s New in Pathogenesis and Management
https://pmc.ncbi.nlm.nih.gov/articles/PMC6139322/
The immunological mechanisms involved in PLE, with mediators from the innate and adaptive immune system, are very similar, either from the histological or the biochemical point of view, to the ACD ones. […] Recently, to reinforce this concept, some of the inflammatory mediators involved in ACD have been demonstrated also in PLE. […] The increase of IL-36s in skin and peripheral blood of PLE patients indicates the activation of local and systemic immune response, as found in multiple inflammatory skin conditions. […] These mediators, named as defensins, cathelicidin, ribonuclease 7 and psoriasin, in light of the imbalance induced by UVR on keratinocytes and skin microbiome, have also been investigated in PLE. […] The first line of treatment for PLE includes sun avoidance, sunscreens and topical corticosteroids.
#2 Polymorphous Light Eruption Symptoms, Causes, and Treatment
https://www.healthline.com/health/polymorphous-light-eruption
Polymorphous light eruption (PMLE) is an allergic reaction to sunlight or other sources of ultraviolet (UV) light. Its the most common skin condition caused by sunlight. A study across Europe found that PMLE affects as much as 18 percent of the population there. […] The exact cause of PMLE isnt known, but genetics are thought to play a role. Experts have suggested it may also be at least partly associated with hormones, such as estrogen, low vitamin D, and factors within your microbiome. […] While the causes of PMLE are still under investigation, the rash is brought on by UV light. […] It’s important to note that, while UVA exposure is the typical cause, the rash can be a result of UVA or UVB exposure. This means that glass windows wont provide enough protection from the sun to prevent a PMLE reaction.
#2 Polymorphous Light Eruption: Symptoms, Causes, Diagnosis, Treatments
https://resources.healthgrades.com/right-care/skin-hair-and-nails/polymorphous-light-eruption
Polymorphous light eruption is a form of sun allergy. It is a seasonal rash that appears in the spring or summer. People may call it a sun poisoning rash, but it is actually an immune reaction. This article explains polymorphous light eruption symptoms, causes, diagnosis, and treatment. […] PMLE is idiopathic, meaning there is no known cause. The most likely theory is that it is a delayed hypersensitivity reaction to an endogenous antigen after UV light. This allergic or immune reaction includes exposure to sunlight and artificial UV light sources. […] Experts also lack a clear understanding of the skin hardening effect. It could result from developing an immune system tolerance to sun exposure. However, it could also occur as the skin tans and thickens with sun exposure, providing more of a barrier to sunlight.
#2 Polymorphous light eruption – Augusta HealthSearchClose SearchSearch IconSearch IconClose Search IconMobile Menu IconMobile Menu Close IconInstagramFacebookTwitterYoutube
https://www.augustahealth.com/disease/polymorphous-light-eruption/
Polymorphous light eruption, also known as polymorphic light eruption, is a rash caused by sun exposure in people who have developed sensitivity to sunlight. […] The exact cause of polymorphous light eruption isnât well-understood. The rash appears in people who have developed sensitivity to components of sunlight, and in particular ultraviolet (UV) radiation from the sun or other sources, such as tanning beds or tanning lamps. This sensitivity is called photosensitivity. It results in immune system activity that causes a rash. […] Sensitivity to sunlight lessens with repeated exposure in polymorphous light eruption. Features of polymorphous light eruption are somewhat predictable: An episode is most likely to occur after the first one or two exposures to sunlight after a long period of no exposure. This usually means that an episode occurs during the spring or early summer or during a winter vacation in a sunnier location. Episodes are less likely to occur as the summer progresses. After the first episode of polymorphous light eruption, additional episodes are likely to recur each spring or early summer. Some people gradually become less sensitive over several years and eventually no longer experience the annual rash.
#2 Polymorphous light eruption – Symptoms, Causes, Images, and Treatment Options
https://www.epocrates.com/online/diseases/626/polymorphous-light-eruption
Polymorphous light eruption typically onsets during adolescence and young adulthood. […] Typically, manifests after exposure to intense ultraviolet radiation (UVR); clinical symptoms last several days and remission occurs without complication. […] Polymorphic light eruption occurs in 18% of Europeans and does not show higher prevalence with increasing latitude: multicenter survey of 6,895 individuals residing from the Mediterranean to Scandinavia. […] The heritability of polymorphic light eruption. […] Aberrant gene expression with deficient apoptotic keratinocyte clearance may predispose to polymorphic light eruption. […] Unique profile of antimicrobial peptide expression in polymorphic light eruption lesions compared to healthy skin, atopic dermatitis, and psoriasis.
#2 A clinicoepidemiological study of polymorphic light eruption – Indian Journal of Dermatology, Venereology and Leprology
https://ijdvl.com/a-clinicoepidemiological-study-of-polymorphic-light-eruption/
Polymorphic Light Eruption is an abnormal cutaneous response which occurs on exposure to sunlight. The reported prevalence in various cohort studies from England, Sweden and Singapore varies from 10-20% and 26% in a study by Fotiades et al. No such data however, is available from our country even though the exposure to sunlight is high. […] PLE is considered to be a disease of fair-skinned individuals with skin types I to IV. It is less common in very dark-skinned individuals in America, India and Pakistan. In our study, 96% of the patients were of skin types IV to VI which explains its low prevalence (0.56%). […] The majority of the cases were from the city of Varanasi where the study was conducted. Its latitude is 25 o north and longitude 83 east. The prevalence of PLE is said to be higher in regions away from the equator because of the variation in the proportion of ultraviolet A and B radiations at different latitudes. Sunlight was the precipitating factor in 46.82% of the cases, the heat of an open fire in 2.73%, both of these in 19.09% although the precipitating factor was not known in 31.36% of the cases. […] Inheritance of PLE is probably polygenic or through a dominant single gene. Family history of PLE was found in 10% of the cases in the present study but varied from 6.25-12% in the studies conducted by Ross and Millard.
#2 Polymorphic Light Eruption (PMLE): Symptoms and Treatment
https://patient.info/skin-conditions/sun-and-sunburn/polymorphic-light-eruption
Polymorphic light eruption is a skin rash that can happen when you go out in the sun. […] PMLE tends to happen when you go out in the sun in the spring or early in the summer, when your skin is not used to sunshine. The rash may also occur if you go on holiday to a sunny place. It is thought that in people who get PMLE, there is an immune system reaction in the skin which is triggered by UVA. […] Sunlight contains various types of rays (radiation). The ones which can cause PMLE are ultraviolet (UV) light and visible light. UV light has two types, UVA and UVB. […] While sunburn is caused by UVB, it is UVA which causes PMLE. […] It is not known exactly how the sunlight causes PMLE, or why some people get PMLE and others don’t. Some studies have suggested that it is more common in people who smoke or drink six or more alcoholic drinks a week.
#2 Polymorphic Light Eruption – StatPearls – NCBI Bookshelf
https://www.ncbi.nlm.nih.gov/books/NBK430886/
Polymorphic light eruption is the most common form of immunologically mediated photosensitivity dermatoses. […] The cause of polymorphic light eruption is unknown. It is postulated that there is a delayed hypersensitivity reaction to an endogenous antigen expressed after exposure to sunlight or artificial sources of ultraviolet (UV) radiation. […] Theories must account for increased prevalence in women and for the hardening effect of on-going exposure to ultraviolet radiation.
#3 Sun rash: What it is, symptoms, causes, and treatments
https://www.medicalnewstoday.com/articles/sun-rash
A sun rash known medically as a polymorphic light eruption is a skin reaction due to sun exposure. […] Polymorphous light eruption is an immune-mediated rash that typically appears in the spring or summer. Experts suggest that occurs when a person has a delayed hypersensitivity reaction to an antigen expressed after exposure to sunlight or artificial sources of ultraviolet (UV) radiation. […] Research suggests hypersensitivity to the sun is the main possible cause.
#3 2013.3-29.Polymorphous – Our Dermatology Online
https://www.odermatol.com/issue-in-html/2013-3-29-polymorphous/
Polymorphous light eruption is the most common idiopathic photodermatosis. […] Polymorphous Light Eruption (PMLE), also termed Polymorphic Light Eruption, is the most common photodermatosis encountered in clinical practice. […] Pathogenic mechanisms in PMLE have not been fully elucidated. An abnormal immunological response of Gell and Coombs type IV to a sunlight-induced cutaneous neoantigen, first proposed in 1942, because of the delayed reaction time and histological appearance, remains a favored hypothesis, although possible abnormalities of arachidonic acid metabolism have also been suggested as being responsible. […] Most authors agree that PMLE results from delayed cell-mediated hypersensitivity to some unknown sunlight-induced antigen.
#3 Polymorphous Light Eruption: Practice Essentials, Pathophysiology, Etiology
https://emedicine.medscape.com/article/1119686-overview
Polymorphous light eruption (PMLE) is an acquired disease and is the most common of the idiopathic photodermatoses. […] The etiology of PMLE is not fully known but is likely to be multifactorial. That PMLE clusters in families suggests a genetic component. […] The UVA light spectrum is the most common causative factor in polymorphous light eruption (PMLE). Other wavelengths, including UVB or even visible light, may also induce PMLE in some individuals. […] Overall, family history is positive for PMLE in about 15-20% of patients. However, Native Americans have a hereditary form of PMLE with apparent autosomal dominant inheritance; 75% reveal disease in a family member.
#3
https://sunsaferx.com/blogs/health-wellness/polymorphous-light-eruption-treatment-prevention?srsltid=AfmBOorThUTpxIZ3RdGT-CTKMDadzNmvYOVV8gxkQpd4y77mfJv7G0Ta
Polymorphous light eruption, or PLE, is the most common skin disease caused by sunlight. […] PLE arises spontaneously in people who are sensitive to ultraviolet light and is characterized as one type of photodermatosis. […] The mechanism of PLE is not well understood. It is thought to be caused by a type IV delayed hypersensitivity reaction by the immune system to an allergen produced by the bodyin this case, in response to the damage from sun exposure, resulting in skin inflammation. […] PLE tends to run in families and often people who are affected will have relatives who are also affected. […] For people who have shown symptoms of polymorphous light eruption previously, 30 minutes or less of sun exposure may be enough to cause a reaction. […] It can be triggered by visible sunlight and both UVA (ultraviolet A) and UVB (ultraviolet B) rays, tanning beds, and even exposure to fluorescent lighting. […] Because UVA rays provoke PLE, symptoms may even appear after sun exposure through a glass window or thin clothing.
#3 Polymorphous light eruption: Pictures and treatments
https://www.medicalnewstoday.com/articles/polymorphous-light-eruption
Polymorphous light eruption (PLE) is a common skin rash that occurs due to sunlight exposure. […] Researchers are not sure what causes PLE, but they believe it may occur due to a reaction by the immune system. […] It is possible that people with PLE have some resistance to this UV-induced immunosuppression, which could result in skin inflammation, a 2022 review of research suggests. […] There may also be a link with estrogen, according to the 2022 review. This hormone may prevent UV radiation from suppressing the skin’s immune responses. […] In up to 50% of cases, people with PLE have family members who also have the condition. This may suggest a genetic component, but researchers have not proven this.
#3 Polymorphous light eruption – Augusta HealthSearchClose SearchSearch IconSearch IconClose Search IconMobile Menu IconMobile Menu Close IconInstagramFacebookTwitterYoutube
https://www.augustahealth.com/disease/polymorphous-light-eruption/
Polymorphous light eruption, also known as polymorphic light eruption, is a rash caused by sun exposure in people who have developed sensitivity to sunlight. […] The exact cause of polymorphous light eruption isnât well-understood. The rash appears in people who have developed sensitivity to components of sunlight, and in particular ultraviolet (UV) radiation from the sun or other sources, such as tanning beds or tanning lamps. This sensitivity is called photosensitivity. It results in immune system activity that causes a rash. […] Sensitivity to sunlight lessens with repeated exposure in polymorphous light eruption. Features of polymorphous light eruption are somewhat predictable: An episode is most likely to occur after the first one or two exposures to sunlight after a long period of no exposure. This usually means that an episode occurs during the spring or early summer or during a winter vacation in a sunnier location. Episodes are less likely to occur as the summer progresses. After the first episode of polymorphous light eruption, additional episodes are likely to recur each spring or early summer. Some people gradually become less sensitive over several years and eventually no longer experience the annual rash.
#3 Polymorphous light eruptions – Indian Journal of Skin Allergy
https://skinallergyjournal.com/polymorphous-light-eruptions/
Certain genes in normal skin such as complement 1s subunit, scavenger receptor-B1 (SCARB-1), caspase-1 (CASP-1) and fibronectin (FN-1)-1 are associated with apoptotic cell clearance. […] A deficiency of Vitamin D3 is considered a risk factor to increase disease susceptibility by impairing immune function and increasing inflammation. […] The newer concepts in the immunopathogenesis of PMLE include loss of UV-induced immunosuppression, involvement of the IL-1 family of cytokines, activation of toll-like receptors, and dysregulation in the levels of antimicrobial peptides.
#3 Polymorphic light eruption (PMLE) â DermNet
https://dermnetnz.org/topics/polymorphic-light-eruption
Polymorphic light eruption (PMLE) is a seasonal, acquired, idiopathic photodermatosis occurring in spring and early summer. […] What causes polymorphic light eruption? There is a genetic susceptibility in 15-46% of cases where a positive family history is reported. PMLE is a delayed hypersensitivity reaction in the skin to unknown endogenous cutaneous photo-induced antigens. This abnormal response to ultraviolet (UV) light means affected patients develop an inflammatory response to an endogenous photo-induced antigen. The following factors must be considered when determining pathogenesis and when implementing protective measures: It is primarily caused by either UVA (75-90%) or UVB light alone or UVA and UVB light concurrently. It is rarely caused by visible light. UVA can penetrate window glass and some sunscreens do not protect against it. Some patients have reported a response to UVC from welding arcs. […] Because PMLE is more prevalent in women than men, it is hypothesized that there is a hormonal component to its pathogenesis. Estradiol may act as an inhibitor to the UV light immunosuppression which would normally aid in reducing hypersensitivity reactions.
#4 Polymorphous light eruptions – Indian Journal of Skin Allergy
https://skinallergyjournal.com/polymorphous-light-eruptions/
Polymorphous light eruption (PMLE) is the most common, immunologically acquired photo-dermatosis due to delayed hypersensitivity reaction to sunlight. […] Genetic susceptibility and environmental exposure play an important role in the pathogenesis of PMLE. […] The exact etiopathogenesis of polymorphous light eruption (PMLE) is still not well understood, but the disease is linked to a delayed-type (type IV) hypersensitivity reaction to one or more endogenous photo-antigens. […] Dysregulation of AMPs is found in skin lesions of PMLE, which triggers the release of IL-31 from keratinocytes and is an important cytokine in the pathogenesis of pruritic lesions in these patients. […] In PMLE, failure of this UV-induced immunosuppression leads to reduced production of neutrophil-derived TNF-, IL-4, and IL-10, failure of Langerhans cell migration, and lack of neutrophil infiltration.