Generalized granuloma annulare treated with methylaminolevulinate photodynamic therapy.

Granuloma annulare (GA) is a non-infectious granulomatous dermatosis characterized by annular papules and rarely nodules and plaques, arising on the dorsa of the hands, feet, elbows and knees; it is usually chronic and asymptomatic. The aetiology of GA is unknown, although many hypotheses have been postulated. About 10% of patients affected by GA present the generalized subtype, characterized by a later age of onset and a chronic course with a low tendency to spontaneous resolution. The widespread papular eruption develops on the trunk and upper or lower limbs. Generalized GA is very disfiguring because of the extensive dissemination of the lesions. The response to various treatments, namely topical and intralesional corticosteroids, topical tacrolimus, dapsone, isotretinoin, etretinate or hydroxychloroquine, is usually unsatisfactory. We report 3 cases with long-lasting generalized GA responding to methylaminolevulinate photodynamic therapy.