Pyoderma gangrenosum and Crohn's disease. Eight cases and a review of the literature.

Abstract

Pyoderma gangrenosum is an ulcerative cutaneous lesion of unknown cause that has been associated with chronic diseases. Its association with inflammatory bowel disease has classically been with chronic ulcerative colitis; however, scattered cases have appeared in which pyoderma gangrenosum has accompanied Crohn's disease. Collected series have indicated an incidence varying between 0.16 per cent in the Mayo Clinic series of 1954 to 1.5 per cent in the Cleveland Clinic series of 1975. We have reviewed the records of eight patients with pyoderma gangrenosum and Crohn's disease who were seen at the Lahey Clinic between 1957 and 1980. During this period, 961 patients with Crohn's disease were seen (an incidence of 0.8 per cent). The ages of the patients ranged between 16 and 65 years. In two of the eight patients, the onset of pyoderma gangrenosum was coincident with the onset of the bowel symptoms; in the remaining six patients, the onset of pyoderma gangrenosum averaged 7.3 years after the onset of bowel disease. The diagnosis of Crohn's disease was made histopathologically for five patients; for the rest, the diagnosis was clinical. Lesions of pyoderma gangrenosum were seen on the legs of all eight patients; two patients had additional lesions of the trunk. In five patients, the activity of the skin lesions paralleled that of the bowel disease. Distribution of Crohn's disease in patients with pyoderma gangrenosum is similar to that previously reported—five with ileocolitis, two with colitis, and one with ileitis. Other extraintestinal manifestations of Crohn's disease in this group of patients were perianal disease in two, erythema nodosum in one, arthritis in one, and iritis in one. The diagnosis of pyoderma gangrenosum was confirmed pathologically in only one patient, emphasizing the subjective clinical nature of this diagnosis. This report represents the largest detailed series of patients with pyoderma gangrenosum and Crohn's disease to date.