Pyoderma gangrenosum as a first presentation of inflammatory bowel disease.

Up to 40% of patients with inflammatory bowel disease (IBD) develop an extraintestinal manifestation of the disease with the skin being the most commonly involved organ. Pyoderma gangrenosum (PG), an autoinflammatory non-infectious neutrophilic dermatosis, occurs in 1-2% of patients with IBD. PG can follow a course independent to that of the bowel disease, however, most reported cases describe PG occurring in patients with an established diagnosis of IBD. We present a case of a young patient who presented with axillary skin ulceration, which was subsequently diagnosed as PG. On further investigation for a possible underlying cause, she was found to have Crohn's disease. She had not developed any preceding change in her bowels and did not have abdominal pain; the IBD was diagnosed on endoscopic findings. This case is also unusual for the distribution of the PG lesions that typically occur in the lower limbs.