Mycophenolate mofetil is an effective treatment for peristomal pyoderma gangrenosum.

An 18-year-old woman with Crohn disease was referred by her gastrointestinal surgeon for treatment of possible peristomal pyoderma gangrenosum (PPG). She had undergone a total proctocolectomy with ileoanal anastomosis when she was 10 years old. Her inflammatory bowel disease (IBD) had been quiescent for a few years; however, she had an acute onset of anal fistulas and pouchitis, which led to a revision of the S pouch and an ileostomy formation. Two weeks after surgery, tenderness occurred around the stoma site, and intravenous infliximab therapy was initiated. During the initial infusion, shortness of breath developed, and the infliximab therapy was discontinued. Physical examination findings revealed an erythematous, indurated area without ulceration inferomedial to the ostomy site. Superficial erosion of the incision wound and central dehiscence were also evident. The perineal and buttocks regions were erythematous, and there was pus exuding from the Seton drains. The results of laboratory investigations included hemoglobin and hematocrit levels of 11.1 g/dL and 33.5%, respectively. The Westergren erythrocyte sedimentation rate was 39 mm/h (reference value, 20 mm/h). The rest of the laboratory findings were within normal limits. Ileoscopy and visualization of the stoma revealed no active Crohn disease. Over the course of several weeks, 3 ulcers with violaceous undermined borders and granulation tissue in the bases developed. The largest ulcer, which was located medially at the inferior margin of the stoma, measured 4.5 3.5 cm in diameter; the lateral ulcer measured 2.5 cm in diameter; and the midline ulcer along the healing incision wound measured 1 cm in diameter, with skip areas attached by strips of intact skin (Figure 1). Several immunomodulatory drugs, such as intravenous infliximab (5 mg/kg), oral prednisone (40 mg), azathioprine (100 mg/d), and dapsone (50 mg/d), were administered. During the infliximab infusion, the patient developed shortness of air and angioedema, which were treated with discontinuation of the infusion and with diphenhydramine hydrochloride. Prednisone therapy was unsuccessful, and the patient was beginning to develop cushingoid features. Azathioprine and dapsone therapy resulted in intolerable nausea. Topical 0.1% tacrolimus ointment was prescribed for application to the peristomal and midline ulceration on the days that the patient’s dressings or appliance was changed, but there was little response to the treatment.