ACE in the Hole: Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema as a Cause of Recurrent Abdominal Pain

Abstract

As one of the most prescribed medications in the United States, angiotensin-converting-enzyme inhibitors (ACEI) have a 0.1-0.7% risk of angioedema. Oropharyngeal angioedema is well known and rarer is angioedema of the GI tract, which can present with nonspecific signs of abdominal pain, nausea, or vomiting. We report a case of angioedema of the small bowel in a patient with recurrent abdominal pain and small bowel segmental thickening of the jejunum. A 58-year-old African American woman with a history of hypertension on lisinopril presented with recurrent abdominal pain in the mid-abdomen associated with vomiting and diarrhea. Symptoms would resolve with supportive treatment and she had several admissions for the same complaint over the past year. On exam she was afebrile with normal vitals and a mildly tender but soft abdomen. Laboratory data was remarkable for mild leukocytosis (12.4 WBC/mm3) with normal eosinophils. Infectious workup was negative and she had a normal C-reactive protein level. CT imaging showed segmental thickening of the proximal jejunum with trace ascites. A push enteroscopy was performed that revealed slightly edematous mucosa with erosions. Pathology from the biopsies showed focal areas of eosinophils. Autoimmune antibodies including ANCA, anti-transglutaminase antibodies, and c1-esterase inhibitor testing were negative. Lisinopril was discontinued with resolution of her symptoms and a diagnosis of ACEI small bowel angioedema was made. ACEI small bowel angioedema is a rare side effect of ACEI therapy and can occur at any time during therapy with an ACEI. The diagnosis is made when other more likely causes are ruled out and symptoms resolve on cessation of the drug. Eosinophilic gastritis is an important differential diagnosis but ACEI small bowel angioedema will not present with systemic eosinophilia. Risk factors for ACEI angioedema include female gender, age 40-70, and African American race. C1-esterase inhibitor levels are normal and the jejunum is most commonly affected with associated ascites. The biochemical increase in bradykinin by inhibition of the angiotensin-converting-enzyme is thought to be responsible for the angioedema. Given how common ACEI therapy is prescribed, clinicians should be aware of this potential side effect in a patient taking an ACEI with unexplained recurrent abdominal pain and segmental small bowel wall thickening.2542_A Figure 1. Abdominal CT imaging showing segmental thickening and edema of the jejunum and trace ascites.2542_B Figure 2. Push enteroscopy showing a mildly edematous jejunum.2542_C Figure 3. Jejunal biopsies showing no granulomas and focal areas of eosinophils.