2644 ACE Inhibitor-Induced Visceral Angioedema - A Rare Phenomenon

Abstract

INTRODUCTION: Angiotensin Converting enzyme (ACE) inhibitors are widely used to treat hypertension and congestive heart failure. Common adverse reactions include cough, hypotension and dizziness. Angioedema is a rare reaction that occurs in less than 1% of patients. Most cases of angioedema are involving the lips, tongue, face and airway. More rarely, visceral angioedema can also occur with jejunal involvement. CASE DESCRIPTION/METHODS: A 24-year-old female with recently diagnosed hypertension treated with lisinopril presented for evaluation of abdominal pain, vomiting, and diarrhea. On examination, she had moderate epigastric tenderness with normal bowel sounds and no organomegaly. Labs revealed white blood cells 20 k/mm3, elevated C-reactive protein 34.2 mg/L and normal erythrocyte sedimentation rate 7 mm/hr. Complement levels including C1 esterase inhibitor, C1q and C4 were found to be normal. Stool culture also remained negative. Computed tomography (CT) of the abdomen revealed moderate ascites, marked mucosal thickening of jejunal and ileal loops with adjacent mesenteric edema (Figure 1). Magnetic Resonance Enterography did not reveal any pathological process. A paracentesis was performed with the ascetic fluid analysis revealing a low serum-ascites albumin gradient without infection. Endoscopy with small bowel enteroscopy revealed normal duodenum and jejunum (Figure 2). Jejunal biopsy returned negative for an infectious or inflammatory process. Due to negative diagnostic workup, a diagnosis of ACE inhibitor-induced visceral angioedema was suspected. Patients symptoms quickly improved 24 hours after cessation of lisinopril and she was discharged home. On follow up 4 weeks later, the patient remained symptom-free. DISCUSSION: Visceral angioedema is a rare side effect of ACE inhibitors most commonly affecting the small bowel. The jejunum is most often affected followed by ileum and duodenum. High levels of bradykinin can cause increased vascular permeability within the bowel mucous membrane causing edema. Symptoms commonly include abdominal pain, anorexia, vomiting and diarrhea. Symptoms typically begin 72 hours after starting the ACE inhibitor. Imaging studies show circumferential small bowel thickening with mesenteric edema and ascites. Endoscopic examination is usually normal. Diagnosis is made by exclusion of other etiologies and improvement of symptoms within 48 hours of drug cessation. Treatment includes discontinuation of the offending drug and supportive therapy until symptoms are resolved.