[Pyoderma gangrenosum revealing colonic diverticulitis: Two cases]

The association of pyoderma gangrenosum (PG) with colonic diverticulitis infection (DI) is relatively unknown. Herein, we describe two cases of PG with full recovery after colonic surgery.

Case 1: an 83-year-old man presented with lesions on his legs that had been present for several weeks, and a diagnosis of PG was confirmed histologically. Abdominopelvic computed tomography (CT) performed on account of biological inflammatory syndrome revealed DI complicated by abscesses. Following the failure of two different antibiotic regimens, sigmoidectomy was performed. Postoperatively, the skin lesions healed without local or systemic corticosteroids. Case 2: a 63-year-old woman presented PG resistant to local and systemic corticosteroids and dapsone for several months. A particularly severe flare was accompanied by abdominal pain and inflammatory syndrome. CT revealed perforated sigmoid DI. Sigmoidectomy was performed after failure of drug therapy. The patient's PG subsequently improved and had disappeared without recurrence at 24months.

Both of these cases of PG revealed DI. The hypothesis is that DI constituted a source of colonic inflammation, sending out bacterial antigenic stimuli that resulted in PG through deposition of circulating immune complexes. Removal of this inflammatory source appears to have enabled healing of PG.

DI must be added to the list of systemic diseases associated with PG. In the case of isolated PG, CT may be used to detect asymptomatic DI. Early diagnosis could prevent serious gastrointestinal complications.