Cutaneous granulomatous vasculitis associated with Crohn's disease.

A thirty-nine-year-old man with Crohn's disease of fourteen years' duration developed papules and nodules on his lower extremities which, not infrequently, became purpuric or pustular, and healed with pigmented depressed scars. Histologic examination showed fibrinoid necrosis of the superficial dermal vessels associated with an inflammatory infiltrate consisting mainly of epithelioid histiocytes. Activity of the cutaneous lesions was not correlated with activity of the patient's underlying visceral disease. The cutaneous lesions improved with dapsone therapy combined with prednisone and sulfasalazine. The role of circulating immune complexes in the pathogenesis of vasculitis in Crohn's disease is reviewed.