Polymorphous light eruption

Abstract

Polymorphous light eruption (PLE) is a common idiopathic photosensitivity disorder with an estimated prevalence of 10-20%. It is characterized by an intermittent skin reaction to ultraviolet (UV) radiation exposure, consisting of non-scarring pruritic erythematous papules, vesicles or plaques that develop on light-exposed skin. Despite the different morphology in different individuals, the eruption tends to have a monomorphous presentation in any single subject. The histopathological features of PLE are distinct and comprise a perivascular lymphocytic infiltrate in the dermis, subepidermal oedema and variable epidermal changes. The pathogenesis of PLE is not well known, but findings suggest that it is a delayed-type hypersensitivity reaction to one or more UV-modified cutaneous antigens. The principal action of PLE is mainly in the UVA region, although some subjects exhibit sensitivity to UVB alone or to both UVA and UVB radiation at the same time. Preventive measures in PLE include the regular use of photoprotective methods combined with graduated exposures to natural sunlight. The induction of immune tolerance by phototherapy and photochemotherapy are useful prophylactic methods in moderate to severe cases. The role of systemic agents in the management of PLE is under investigation. This article reviews the epidemiological, pathogenetic and clinical aspects of PLE and discusses recent advances in the diagnostic approach and management of this condition.

A Clinico-Pathological Study of Poly Morphous Light Eruption

“…This is the first description of polymorphous light eruption (PMLE). The term PMLE was introduced by Rasch in 1990 [1]. PMLE belongs to the idiopathic photo dermatoses together with actinic prurigo, hydroa vacciniforme, chronic actinic dermatitis and solar urticaria [2,3].…”

“…Holtze suggested that the action spectrum may vary for the different skin lesions. It may be due to UVB alone or to both UVA and UVB [1]. PM-LE appears to be an immunologically mediated response possibly a delayed hypersensitivity phenomenon to a photo antigen induced or up regulated in the skin after sun exposure [16].…”

Fotodermatoses Autoimunes Parte I - Fisiopatologia e Diagnóstico

“…O mesmo pode ocorrer se o teste for realizado tardiamente, durante a primavera ou verão, devido ao fenóme-no de tolerância e fotoendurecimento. 85 Assim, os fototestes devem ser preferencialmente realizados no início da primavera. As lesões poderão ser induzidas em 60% -90% dos casos, dependendo do método e da radiação utilizada.…”

Nichthereditäre Photodermatosen im Kindesalter

“…10% aller PLD bereits in der Gruppe der Klein-und Schulkinder bis zum vollendeten 10. Lebensjahr, sodass dieser Erkrankung auch aus pädiatrisch-dermatologischer Sicht eine hohe Relevanz zukommt [36].…”