Photopatch Testing

Abstract

Photopatch testing is a procedure that combines patch testing with UV irradiation. It is primarily indicated to study photoallergic contact dermatitis, but it can also contribute to establish a correct diagnosis of any exposed site dermatitis or systemic drug photosensitivity. Photopatch testing has been standardized with the input of the European Society of Contact Dermatitis and European Society of Photodermatology, but it is still seldom performed. It consists on the application of two sets of allergens for 1 or 2 days, irradiation of one set at D1 or D2 with 5 J/cm 2 of UVA, and readings immediately after irradiation and two or more days thereafter. A European photopatch test