Researchers presented the case study of a patient who had duodenal edema secondary to previously undiagnosed hereditary angioedema in Internal Medicine.

The 64-year-old woman presented with recurrent severe epigastric pain. She did not have any other medical complaints. A computed tomography scan revealed a thickened duodenal wall with ascites; an esophagogastroduodenoscopy showed mucosal and submucosal edema in the descending duodenum. 

The patient revealed that both she and her father had a history of recurrent swelling of the face and lips. Laboratory investigations demonstrated low levels of C4 and C1-esterase inhibitors as well as low C1-esterase inhibitor functional activity. She was duly diagnosed with type 1 hereditary angioedema. Her symptoms resolved with intravenous hydration and a 2-day fast. 

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Around half of all patients with hereditary angioedema present solely with moderate to severe abdominal pain. This is consistent with the presentation of the patient in this case study. The patient was revealed to have duodenal edema only upon imaging studies. 

Read more about hereditary angioedema etiology 

Many patients undergo unnecessary exploratory abdominal surgeries due to the most common misdiagnosis of this condition: small bowel obstruction. This is especially common among middle-aged patients, since hereditary angioedema is typically diagnosed in young adults. According to the authors, “[hereditary angioedema] should be considered a differential diagnosis, even in middle-aged patients, if they present with recurrent abdominal pain.”

Occasionally, detailed history-taking may reveal recurrent swelling episodes in other parts of the body, such as the larynx. In the case of this patient, she stated that she suffered from recurrent face and lip swelling. Patients who experience recurrent swelling episodes may also demonstrate signs of psychological distress. 

There are 3 main diagnostic criteria for hereditary angioedema. The first is a typical manifestation of hereditary angioedema, such as recurrent edema. The second is low functional levels of C1-esterase inhibitor activity (less than 50%). The third is a positive family history of the condition. 


Kawara F, Matsuura T, Yamanaka K, Nishioka C. A case of duodenal edema-related undiagnosed hereditary angioedemaIntern Med. Published online November 23, 2022. doi:10.2169/internalmedicine.0869-22