The bowel-associated dermatosis--arthritis syndrome.

A 46 year old man with Crohn's disease developed a widespread pustular eruption associated with intermittent fever and arthritis. Histological examination demonstrated cutaneous vasculitis with leukocytoclasia, and IgM and C3 on direct immunofluorescence. This is characteristic of the bowel-associated dermatosis-arthritis syndrome, also known as the bowel bypass syndrome without bypass, a recently described complication of inflammatory bowel disease. This is the ninth case reported to date.