A 60-year-old woman with recurrent papular and vesiculobullous lesions of erythema elevatum diutinum responded to treatment with 100 mg of oral niacinamide three times a day and 250 mg of tetracycline hydrochloride four times a day. Prior therapy with 2.5 mg of dexamethasone daily and 1.0 g of erythromycin daily had been unsuccessful. After four weeks, tetracycline therapy was discontinued, and niacinamide alone sufficed to suppress the disorder. Recurrent lesions developed whenever niacinamide therapy was stopped.