Leukocytoclastic vasculitis caused by drug additives.

Chronic cutaneous small vessel (leukocytoclastic) vasculitis (LCV) is a process believed to be related to the presence of circulating immune complexes. The most frequent causes and associated disorders are medications, infections, collagen vascular disorders, paraproteinemias, and, rarely, neoplasia. Reports of food or food additives as a causative factor for LCV have appeared but are rare. We report a patient with chronic cutaneous LCV in whom the presumed cause was an excipient (a dye) used in the capsule form of lithium carbonate. Furthermore, ingestion of foods containing dyes results in a disease flare in our patient.