Isolated Intestinal Involvement of Angioedema Induced by ACE Inhibitor

Abstract

Purpose: 58-year-old obese African-American woman with metabolic syndrome presents to our hospital with progressively worsening acute on chronic non-radiating periumbilical pain with abdominal distension, nausea and non-bloody emesis, which has progressed over the past six months. Physical exam was notable for an uncomfortable afebrile black woman, normotensive, with tachycardia and tachypnea. She had no peripheral rash or edema, no mucosal edema, and had clear lung fields on auscultation. Her abdomen had no surgical scars, was obese and distended with hypoactive and high pitched bowel sounds, and was diffusely tender with guarding and rebound tenderness. Rectal exam revealed brown guaiac negative stool in an empty rectal vault. Laboratory investigation revealed a normal complete blood count, comprehensive metabolic panel, amylase, lipase, and slightly elevated lactate at 4.2 mmol/L. Contrast enhanced CT abdomen was revealed contiguous distal jejunal to ileal small bowel enhancement and thickening with associated small bowel dilation of the affected areas without a transition point of obstruction. In light of her presentation and risk factors for vascular disease, a CT angiogram was performed 6 hours after her initial CT abdomen to evaluate for mesenteric ischemia. Remarkably, this exam revealed complete resolution of bowel wall enhancement, thickening, and dilation, along with patent mesenteric arteries. During this time, patient's clinical symptoms also completely resolved. Upon reviewing patient's history, patient started having symptoms after initiation of lisinopril approximately 9 months prior to presentation. C1-esterase, C1q, and C3 complement levels were subsequently found to be normal. Our suspicion for ACE inhibitor induced intestinal angioedema was confirmed after patient remained asymptomatic with discontinuation of lisinopril. ACE inhibitor induced angioedema typically involves the extremities, face, and upper airways. It is caused by quantitative or qualitative deficiency of C1-esterase protein, which inhibits vasodilators such as bradykinin. Concomitant gastrointestinal involvement is common; however, it is rarely the sole manifestation of this disease. This disease carries a high mortality if untreated and may even lead to unnecessary surgical exploration if misdiagnosed. As such, clinical awareness of this entity as a cause of acute abdomen is paramount in providing the best care for these patients. Conclusion: Isolated intestinal involvement of ACE-inhibitor induced angioedema can also occur without typical features of facial or extremity swelling. Knowledge of such manifestation can improve patient outcomes.