Vasculitis involving muscle associated with Crohn's colitis.

A case of Crohn's colitis is described in a patient who demonstrated multiple extraintestinal complications, including erythema nodosum, pyoderma gangrenosum, and aphthous oral ulcerations. Our patient simultaneously developed an unusual vasculitis in muscle. Small vessels were affected by necrosis, and polymorphonuclear leukocyte infiltration was appreciated. Leukocytoclastic was suggested by these features and the additional finding of small amounts of nuclear debris. A strong immunofluorescence to antihuman C3 was demonstrated in the affected vessel walls. We did not find circulating IgG immune complexes in serum with the Raji cell assay. The implication of the finding of leukocytoclastic vasculitis in muscle, associated with Crohn's colitis, is discussed.