Lichen planus following procainamide-induced lupus erythematosus.

A case of procainamide-induced lupus erythematosus with prominent cutaneous features is presented. The patient subsequently showed typical lesions of lichen planus, which has been associated with spontaneously occurring lupus erythematosus, but not previously reported with drug-induced lupus or as a result of procainamide therapy. A review of the immunologic alterations induced by procainamide raises questions about possible mechanisms causing the lupus and lichen planus.