{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T14:39:24Z","timestamp":1777300764164,"version":"3.51.4"},"reference-count":15,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T00:00:00Z","timestamp":1777248000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:p>Hereditary angioedema (HAE) due to C1 esterase inhibitor (C1-INH) deficiency is a rare bradykinin-mediated disease characterized by recurrent episodes of angioedema. Gastrointestinal manifestations can resemble an acute abdomen and are often misdiagnosed, contributing to delayed recognition. We describe a 35-year-old man with two previous self-limited episodes of abdominal pain with diarrhea over the preceding year, beginning in August 2024, each lasting approximately five days, both of which were diagnosed as acute gastroenteritis and treated with symptomatic intravenous therapy. He presented with acute paroxysmal right lower quadrant abdominal pain and watery diarrhea, without fever, nausea, or vomiting. Contrast-enhanced abdominal computed tomography revealed segmental ileal wall edema with ascites, showing slight progression on repeat imaging later the same day. Laboratory analysis demonstrated leukocytosis with neutrophilia and significantly elevated D-dimer levels. Complement testing showed a significantly reduced C4 concentration (0.08\u202fg\/L) and a normal C3 level (0.84\u202fg\/L), raising suspicion of HAE. Further evaluation confirmed profoundly decreased functional C1-INH activity (&amp;lt;7%) and a reduced C1-INH antigen level (18.89\u202f\u03bcg\/mL), establishing a diagnosis of type I HAE. The patient improved following supportive and antispasmodic treatment, and no HAE-specific bradykinin-targeted therapy was administered during this admission. This case emphasizes that recurrent, self-limited abdominal pain accompanied by imaging evidence of transient small-bowel wall edema and ascites should prompt consideration of abdominal HAE. Early assessment of complement C4 is a practical screening strategy that enables timely confirmatory testing and minimizes the likelihood of repeated misdiagnosis.<\/jats:p>","DOI":"10.3389\/fmed.2026.1818323","type":"journal-article","created":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T13:44:31Z","timestamp":1777297471000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Recurrent self-limiting abdominal pain with bowel wall edema misdiagnosed as gastroenteritis: a case report of C1-inhibitor-deficient hereditary angioedema"],"prefix":"10.3389","volume":"13","author":[{"given":"Binlong","family":"Zhang","sequence":"first","affiliation":[{"name":"Department of Gastroenterology, Yueqing People\u2019s Hospital","place":["Yueqing, Zhejiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Haocheng","family":"Zhao","sequence":"additional","affiliation":[{"name":"Department of Hematology, Yueqing People\u2019s Hospital","place":["Yueqing, Zhejiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,4,27]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"1136","DOI":"10.1056\/NEJMra1808012","article-title":"Hereditary angioedema","volume":"382","author":"Busse","year":"2020","journal-title":"N Engl J Med"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"66","DOI":"10.1172\/jci125378","article-title":"The hereditary angioedema syndromes","volume":"129","author":"Schmaier","year":"2018","journal-title":"J Clin Invest"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"170","DOI":"10.1007\/s12016-016-8543-x","article-title":"Genetics of hereditary angioedema revisited","volume":"51","author":"Germenis","year":"2016","journal-title":"Clin Rev Allergy Immunol"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"717","DOI":"10.1056\/NEJMoa1605767","article-title":"Inhibiting plasma kallikrein for hereditary angioedema prophylaxis","volume":"376","author":"Banerji","year":"2017","journal-title":"N Engl J Med"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"1242","DOI":"10.1056\/NEJMoa1915035","article-title":"Antisense inhibition of Prekallikrein to control hereditary angioedema","volume":"383","author":"Cohn","year":"2020","journal-title":"N Engl J Med"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"404","DOI":"10.1007\/s12016-021-08845-6","article-title":"Biomarkers in hereditary angioedema","volume":"60","author":"Porebski","year":"2021","journal-title":"Clin Rev Allergy Immunol"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"1079","DOI":"10.1016\/s0140-6736(23)00350-1","article-title":"Efficacy and safety of garadacimab, a factor XIIa inhibitor for hereditary angioedema prevention (VANGUARD): a global, multicentre, randomised, double-blind, placebo-controlled, phase 3 trial","volume":"401","author":"Craig","year":"2023","journal-title":"Lancet"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"2108","DOI":"10.1001\/jama.2018.16773","article-title":"Effect of Lanadelumab compared with placebo on prevention of hereditary angioedema attacks","volume":"320","author":"Banerji","year":"2018","journal-title":"JAMA"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"1131","DOI":"10.1056\/NEJMoa1613627","article-title":"Prevention of hereditary angioedema attacks with a subcutaneous C1 inhibitor","volume":"376","author":"Longhurst","year":"2017","journal-title":"N Engl J Med"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"21","DOI":"10.1056\/NEJMoa2402478","article-title":"Efficacy and safety of Donidalorsen for hereditary angioedema","volume":"391","author":"Riedl","year":"2024","journal-title":"N Engl J Med"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"1777","DOI":"10.1007\/s40265-019-01206-w","article-title":"Lanadelumab: a review in hereditary angioedema","volume":"79","author":"Syed","year":"2019","journal-title":"Drugs"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"458","DOI":"10.1016\/s0140-6736(22)02406-0","article-title":"An investigational oral plasma kallikrein inhibitor for on-demand treatment of hereditary angioedema: a two-part, randomised, double-blind, placebo-controlled, crossover phase 2 trial","volume":"401","author":"Ayg\u00f6ren-P\u00fcrs\u00fcn","year":"2023","journal-title":"Lancet"},{"key":"ref13","doi-asserted-by":"publisher","first-page":"2879","DOI":"10.1111\/all.14416","article-title":"Lanadelumab demonstrates rapid and sustained prevention of hereditary angioedema attacks","volume":"75","author":"Riedl","year":"2020","journal-title":"Allergy"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"15","DOI":"10.1007\/s12016-021-08839-4","article-title":"The enigma of prodromes in hereditary angioedema (HAE)","volume":"61","author":"Leibovich-Nassi","year":"2021","journal-title":"Clin Rev Allergy Immunol"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"56","DOI":"10.1056\/NEJMoa2400403","article-title":"Normalization of C1 inhibitor in a patient with hereditary angioedema","volume":"391","author":"Peters","year":"2024","journal-title":"N Engl J Med"}],"container-title":["Frontiers in 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