Secondary Polymorphic Eruptions in Allergic Contact Dermatitis

Abstract

10 cases of secondary dissemination of allergic contact dermatitis in the form of erythema multiforme-like or purpura and vasculitis-like lesions are reported. The responsible contact allergens were various constituents of topical applications, such as pyrrolnitrin, sulfonamide, promethazine, balsam of Peru and vioform + ethylenediamine. The clinical patterns and histopathological features of the lesions are described and the possible pathogenetic mechanisms are discussed.