Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema of the Small Bowel-A Surgical Abdomen Mimic

Angioedema is an infrequent complication of the use of angiotensin-converting enzyme inhibitors (ACEi) that has an incidence of up to 0.5%. The oropharynx is most commonly affected. Angioedema of the small bowel is a much rarer occurrence; it uniformly presents with abdominal pain of variable duration.

A 51-year-old man presented to the emergency department (ED) with generalized abdominal pain, emesis, diarrhea, and bloating. Medical history was significant for hypertension and medications included captopril, metoprolol and aspirin. Vital signs and laboratory tests were unremarkable. Due to the presence of significant abdominal tenderness with guarding on examination, a FAST (focused assessment with ultrasound in trauma) examination was performed and revealed free fluid in the abdomen. A computed tomography scan of the abdomen was quickly obtained, which revealed a large amount of simple-appearing free fluid within the abdomen and mucosal edema throughout the small bowel. The patient underwent an emergent diagnostic laparoscopy and was ultimately diagnosed with angioedema of the small bowel, deemed secondary to captopril usage. Captopril was discontinued and symptoms gradually resolved with supportive care. When imaging is obtained in cases such as this one, small bowel submucosal edema and ascites are often present. Supportive care and cessation of ACEi usage are the cornerstones of treatment. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: In patients on ACEi, it is important to keep this diagnosis in mind to potentially avoid an unneeded surgical intervention, as the condition is self-limiting and can be treated primarily with supportive measures.