Pyoderma gangrenosum in a patient with collagenous colitis.

The association between pyoderma gangrenosum and inflammatory bowel disease is well established. Collagenous colitis is one of the microscopic colitides, which are thought to be on the same spectrum of disease as Crohn's disease and ulcerative colitis. Before this study there had been no reported cases of pyoderma gangrenosum in the setting of collagenous colitis. We report a case of a 79-year-old woman with symptomatic collagenous colitis and refractory pyoderma gangrenosum.