Colonic Intussusception and ‘Pseudo’ Colitis: Acute Uncommon Presentations of Hereditary Angioedema

Abstract

Purpose: Angioedema may be hereditary and can involve the gastrointestinal (GI) tract leading to abdominal pain and diarrhea. Intussusception in patients with hereditary angioedema (HAE) is exceedingly rare. We present the 3rd case reported of intussusception in such patients. Case: A 23-year-old African-American female with type 1 HAE presented to the emergency department with abdominal pain, diarrhea, and facial/tongue swelling. Abdominal CT revealed bowel wall thickening of the ascending and descending colon consistent with colitis. Unremarkable stool work-up and continued diarrhea prompted a colonoscopy which was normal. She had been having similar ‘attacks’ yearly since the age of ten, that had increased in frequency over the past year, at times up to twice monthly. Six months ago she underwent a partial colectomy due to colo-colonic intussusception. Edematous bowel wall was noted to be the lead point in the surgical specimen. Similar symptoms had led to multiple emergency visits and repeated CT scans that demonstrated diffuse edematous bowel wall up to 1.5 cm in thickness. Her symptoms subsequently resolved with antihistamines. Abdominal exacerbation of HAE was rendered as the diagnosis and further lab studies revealed an undetectable functional C1 esterase inhibitor, unremarkable C1Q binding assay, and normal C4 and C1Q complement levels. No consideration was given to therapy with C1-esterase inhibitor or fresh frozen plasma as her symptoms had resolved. Upon discharge, she was referred to an immunologist for outpatient evaluation and danazol prophylaxis. Discussion and Conclusion: 70-80% of patients with HAE may experience recurrent ‘abdominal exacerbations’. HAE may be associated with a quantitative (Type 1) or qualitative (Type 2) C1 esterase inhibitor deficiency. This frequently leads to multiple radiological tests typically revealing colitis/ bowel wall edema. Mild ascites, if present, indicates severity of the attack. Differential diagnoses include inflammatory bowel disease (IBD), infectious colitis, and ACE-inhibitor induced angioedema. The latter involves the small bowel with minimal colonic involvement. IBD is generally evident histopathologically while stool studies assist in diagnosing infectious colitis. Severe HAE attacks should be treated with C1-inhibitor concentrate or FFP. Tranexamic acid has been used in certain parts of the world. Prophylactic therapy with Danazol may reduce recurrent attacks. Prompt diagnosis along with appropriate prophylaxis/treatment is likely to decrease frequency of attacks, prevent expensive radiological/endoscopic investigations and minimize unnecessary antibiotics and surgery.