Response of generalized granuloma annulare to high-dose niacinamide.

A patient with generalized granuloma annulare experienced resolution of her lesions after six months of treatment with 1,500 mg/day of niacinamide. Niacinamide seems to be a reasonably safe drug that, even at relatively high doses, is associated with a low incidence of side effects. The participation of a delayed hypersensitivity reaction in the pathogenesis of granuloma annulare and possible mechanisms involving niacinamide in this type of reaction are discussed.