Hereditary Angioedema of the Small Bowel

Excerpt

A 27-year-old woman was referred to our hospital with periumbilical pain and vomiting that had progressed over the preceding 20 days. For the previous 3 months, the patient had been taking cyproterone acetate and metformin for polycystic ovary syndrome. Additionally, she had been receiving interferon therapy for chronic hepatitis B virus infection for 2 years. 1 week later, she experienced a 72-h, self-limited episode of massive swelling of the face and lips (Fig. 1A), along with right-hand swelling. On examination, her abdomen was mildly distended and minimally tender with no peritoneal signs. Except for a markedly high level of D-dimer and mildly high level of C-reactive protein, she had a normal serum complete blood count, creatinine, electrolytes, and liver function tests. Abdominal contrast-enhanced computed tomography (CT) discovered edema of the duodenum (Fig. 1B) after an initial negative upper gastrointestinal endoscopy and colonoscopy. The patient was managed conservatively and improved within 2 days. Three days later, abdominal pain unexpectedly worsened with the initiation of menstruation. Interestingly, abdominal CT confirmed a distal switch from disappearing swelling of the duodenum to emerging swelling of the jejunum (Fig. 1C), which was manifested as migratory and asymmetric swelling of self-relieving. Self-remitting abdominal pain without obvious organic etiology which was recurrent and lasted > 6 h attracted our attention. Thus, the diagnosis of hereditary angioedema (HAE type I) was admitted, which was further defined by depressed levels and reduced functional tests of a C1 esterase inhibitor. HAE is a rare disorder, characterized by attacks of cutaneous and submucosal swelling, which is often caused by an unregulated generation of bradykinin due to plasma deficiency of C1 esterase inhibitor.¹ Although abdominal attacks are a common complaint, diagnosis is particularly challenging when HAE mimics an acute abdomen, usually causing unnecessary surgery.² HAE should be suspected in patients with recurrent angioedema and abdominal pain of unknown origin.³ Therapeutic options include C1 esterase inhibitor replacement and bradykinin antagonists.³ After symptomatic therapy within 1 week for this patient, her face and lips improved spontaneously (Fig. 1D), with repeat CT enteroclysis showing significant reduction in wall thickening of involved parts of the small intestine. Avoidance of estrogen-containing oral contraceptives was recommended and no episodes were noted in the next several years.

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