Residents’ Corner: Pyoderma Gangrenosum at Surge y Sites ROBERT K. FULBRIGHT, M.D. JOHN E. WOLF, M.D. JAIME A. TSCHEN, M.D. FEATURE Abstract. Pyoderma gangrenosum is a necrotizing and ulcerative skin disorder often associated with underlying systemic diseases. The etiology remains obscure, with re- cent investigations emphasizing an altered immune sys- tem. A case report is presented of pyoderma gangre- nosum occurring at surgical sites in the absence of predisposing factors. Pyoderma gangrenosum in this set- ting can mimic infectious causes of wound necrosis. Early recognition of the characteristic lesion morphology may prevent unnecessary treatment directed toward infec- tious agents and facilitate effective control with systemic corticosteroid therapy. Pyoderma gangrenosum (PG) is an uncommon, noninfectious cutaneous disorder of undetermined etiology. The classic clinical description is that of painful, rapidly enlarging ulcers with undermined bluish or purplish-red margins that heal to produce areas of atrophic, cribriform scarring. Histopatho- logic features are unfortunately nonspecific, and the diagnosis is based largely on the characteristic clin- ical morphology. The importance of recognizing PG is twofold. First, it is a well-documented marker of a variety of systemic diseases including arthritis,2 ulcerative colitis-diverti~ulitis,~ Crohn’s d i ~ e a s e , ~ lymph~rna,~ polycythemia verar6 1eukemia-mye1ofibrosis,’ chronic active hepatitis,* multiple myeloma,’ monoclonal Robert K. Fulbright, M.D., Resident, John E. Wolf, M.D., Chairman, and Jaime A. Tschen, M.D., Assistant Profes- sor, are from the Departments of Derma)ology and Pa- thology, Baylor College of Medicine, Houston, Texas. Address reprint requests to Jaime A. Tschen, M.D., Bay- lor College of Medicine, Departments of Dermatology and Pathology, One Baylor Plaza, Houston, TX 77030. I. Drrnrafol. Surcq. Oircol. 11 :9 Septeiirtwr 1985 gammopathy, lo carcinoid tumor,’’ Wegener’s gran- ulomatosis,*2Takayasu’s arteriti~,’~ systemic lupus erythematosu~,’~ atypical dermatitis herpetifor- mis,I5 and diabetes mellitus.I6 Second, there is evi- dence that PG may occur following minor trauma or surgical procedures, with or without these pre- disposing conditions. 17-22 The purpose of this article is to encourage the inclusion of pyoderma gangrenosum in the differ- ential diagnosis of postsurgical wound complica- tions. Early diagnosis of PG occurring after surgery may facilitate prompt, appropriate therapy, thereby avoiding unnecessary and ineffective therapeutic interventions. CASE REPORT A 61-year-old man was admitted for elective coro- nary artery bypass surgery. His past medical his- tory was significant for the development of a large ulcerated lesion at an appendectomy site in 1945. The cause was presumed to be an anaerobic cellu- litis and skin grafting was required. He had no his- tory of gastrointestinal, rheumatologic, hemato- logic, or endocrine disorders. The patient developed shaking chills and a fever of 38.3”C 3 days after coronary artery bypass sur- gery. Antibiotic therapy with cephalosporins had been given since surgery as prophylaxis. On the fifth postoperative day the sternal wound was sur- gically opened due to an apparent infection. Gram’s stain revealed many white blood cells (WBC) but no organisms. Wound cultures were initially nega- tive and eventually grew only rare Staphylococcus epidermidis. A wound in the right groin dehisced 7 883