Polymorphic light eruption

Abstract

Photosenstivity is defined as an abnormal reaction of the skin to exposure of ultraviolet light or visible light. Polymorphic light eruption (PMLE) is the most common photodermatoses seen in children. PMLE is an immunologically mediated disorder which is postulated to occur due to the failure of UV induced immunosuppression and a delayed hypersensitivity reaction to an endogenous, cutaneous neoantigen produced after ultraviolet light exposure. It occurs in healthy children and is characterized by the presence of polymorphic skin lesions such as skin coloured or erythematous, pruritic papules, vesicles and plaques, hypopigmented and eczematous patches in the sun exposed sites, in different individuals. Lesions tend to be monomorphic in a single individual. Photoprotection plays a pivotal role in the management of PMLE. General measures include avoidance of sun exposure, use of protective clothing, wide-brimmed hat, umbrella, sun glasses and a broad spectrum sun screen. Topical steroids and anti-histamines are useful.