Cutaneous polyarteritis nodosa associated with Crohn's disease.

A 13-year-old white girl with Crohn's colitis developed recurrent erythematous tender cords and nodules in the lower and upper extremities. Histologic examination of subcutaneous nodules of the right arm revealed granulomatous panarteritis of two muscular arteries in the subcutis. The patient's resected colon showed granulomatous transmural colitis without vasculitis. The association between Crohn's disease and cutaneous polyarteritis nodosa is reviewed and emphasis placed on histologic evaluation of suspicious subcutaneous nodules for correct diagnosis.