Photochemotherapy of generalized granuloma annulare.

Various forms of treatment for generalized granuloma annulare have been employed with little success. The results of treatment with topical and intralesional corticosteroids, as well as systemic therapy with corticosteroids, salicylates, aspirin, niacinamide, and chloroquine, have been generally disappointing. We describe five patients with generalized granuloma annulare of several years' duration who were treated with oral psoralen plus ultraviolet A irradiation. Lesions were present on the extremities, buttocks, and trunk in the form of macules, papules, and plaques. One patient also had perforating lesions on her thighs. Flattening of the lesions with decreased erythema and pigmentation was noted as early as 1 month after initiation of treatment. Complete clearance was achieved in all patients. Maintenance therapy has been required, resulting in prolonged disease-free intervals. Although the mechanism of action of oral psoralen plus ultraviolet A irradiation in granuloma annulare is unclear, one possibility is selective elimination of the cells that are responsible for initiating the disease.