Polymorphous light eruption in children – clinical presentation, differential diagnosis and treatment

Abstract

Polymorphous light eruption is classified as an immune-mediated photodermatosis. It is the most common cause of photosensitivity in children between 6 and 14 years old. It is characterised by pruritic or tingling erythematous papular or plaque lesions of sunlight-exposed skin which occur in spring or early summer. The first signs of polymorphous light eruption typically appear several hours to days after the first exposure to intense sunlight and take the form of an irritable rash persisting for a few days, and subsiding within a week or two with minimal or no scarring. Its recurrences may have a detrimental impact on the quality of life. Due to the significant heterogeneity of clinical manifestations of polymorphous light eruption, the disorder is relatively challenging to diagnose. The differential diagnoses include photosensitivity associated with lupus erythematosus, solar urticaria, actinic prurigo, erythema multiforme, photocontact allergic dermatitis, and genetic dermatoses. UVA and UVB phototesting followed by histological examination is an important diagnostic tool to objectify light-related symptoms. Once the diagnosis is established, the patient should be monitored and educated on prevention. The management of polymorphous light eruption is based on prevention such as sun protection and sunscreens. The first-line treatment includes glucocorticoids and antihistamines.