C1 inhibitor deficiency and angioedema of the small intestine masqueradingas Crohn's disease

A case of C1 inhibitor deficiency presenting as localized edema of the smal l intestine is described. A 16-year-old, previously healthy woman presented with recurrent attacks of abdominal pain and vomiting following minor abdo minal trauma. Investigations including computed tomography scan and barium studies confirmed localized edema of the jejunum. At laparoscopy, Crohn's d isease was suspected; however, a subsequent enteroscopy was normal. Complem ent levels revealed a low C4 level, and C1 inhibitor deficiency was later c onfirmed. Attacks of abdominal pain began after starting oral contraceptive s and have not returned since stopping the birth control pill. This rare ca use of abdominal pain is examined, and C1 inhibitor deficiency and angioede ma are reviewed.