Question: A 28-year old woman with a 10-year history of indeterminate colitis presented with bloody diarrhea, abdominal pain, severe odynophagia, and perineal skin ulcerations for 3 months. She had previously failed to respond to multiple therapies, including mesalamine, budesonide, azathioprine, infliximab, and adalimumab, and therefore had been recently started on oral prednisone. Review of systems was significant for fevers, fatigue and a 14-kg weight loss. Physical examination revealed an ill-appearing woman with a purulent ulceration of her right tonsillar fossa and diffuse abdominal tenderness. Perineal inspection revealed multiple wellcircumscribed ulcers with violaceous borders located over the labia and the perianal region (Figure A). Blood cultures obtained on admission grew Escherichia coli and antibiotic therapy was initiated. Esophagogastroduodenoscopy revealed ulcerations in the distal esophagus and gastric antrum (Figure B), and colonoscopy showed deep ulcers extending from the sigmoid colon to the terminal ileum. Biopsies were obtained of the tonsillar region and throughout the affected areas of the gastrointestinal tract; biopsies of the perineal ulcers were also obtained (Figure C). What is the most likely cause of the perineal lesions and what are the treatment options? Look on page 696 for the answer and see the GASTROENTEROLOGY web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI.