Hereditary angio-oedema as a rare cause of small-bowel obstruction.

A 52-year-old man with known hereditary angio-oedema (HAE) presented with a 2-day history of progressive severe abdominal pain, distension, nausea, vomiting and constipation. CT of his abdomen and pelvis showed small-bowel obstruction and ascites. HAE is a rare autosomal dominant disorder caused by a C1 esterase deficiency and involves episodic oedema of subcutaneous and mucosal tissues. It commonly affects the face and limbs, causing deformity; the respiratory tract, causing life-threatening laryngeal swelling; and the gastrointestinal tract, causing small-bowel obstruction. An infusion of a C1 esterase inhibitor was given to the patient. His symptoms resolved within 6 hours, and a repeat CT showed complete resolution 24 hours later. Small-bowel obstruction in HAE is often misdiagnosed, leading to ineffective treatment and unnecessary surgery. Therefore, this should be suspected in patients with HAE presenting with an acute abdomen, and clinicians should understand the unique treatment required.