Generalised exanthematous pustular dermatophytids during Trichophyton violaceum tinea capitis

Abstract Dermatophytids are defined as the acute occurrence of noninfectious secondary lesions at distance from a primary dermatophytic infection. They are well‐known after intertrigo of the toes. We report an 8‐year‐old boy, who developed generalised pustular lesions during the treatment of tinea capitis caused by Trichophyton violaceum. He had a rapid response to local corticosteroid ointment, while oral terbinafine was efficient on the scalp condition. Dermatophytids are the result of a type IV delayed hypersensitivity reaction to dermatophytic antigens. They may occur after initiation of an antifungal treatment. Generalised exanthematous pustular dermatophytids is a clinical variant of dermatophytids. They present as nonfollicular, nonconfluent pustules with an erythematous base, of abrupt onset. Main differential diagnoses are acute generalised exanthematous pustulosis and pustular psoriasis. Medical history, clinical presentation, laboratory findings and, if necessary, biopsy will help to distinguish between those conditions. Evolution is rapidly favourable under local or oral corticotherapy and antifungal treatments should not be withdrawn. Dermatophytids are a differential diagnostic of acute generalised pustulosis during tinea capitis.