Hereditary angioedema (HAE) with C1 inhibitor deficiency is a rare disease characterized by unpredictable episodes of tissue swelling (angioedema), which, in most cases, occur first under the age of 18 years, and entail a significant burden of disease not only for the patients but also for their families. Clinical symptoms of HAE are not specific, which may cause difficulties in differential diagnosis. Additionally, if not appropriately treated, HAE attacks can be life-threatening. The international HAE guidelines published so far have focused mainly on adults. A guideline that refers to the age-specific characteristics of pediatric patients, both in terms of diagnosis and management, was therefore needed. The International Steering Committee and Taskforce developed recommendations and provided evidence-based grading based on expert opinion and strength of evidence. Recommendations were presented to, discussed, and electronically voted by healthcare professionals during the 14th C1 Inhibitor Deficiency and Angioedema Workshop in Budapest, Hungary, 2025. This international guideline will ensure early diagnosis, standardized and up-to-date treatment, and promote the availability of effective therapies for all pediatric patients affected with this rare disease. It also draws attention to the importance of establishing HAE centers and registries, which solicit specialist care and research of the disease.
Keywords: C1 inhibitor deficiency; acute treatment; bradykinin; complement test; comprehensive care; genetic testing; hereditary angioedema; long‐term prophylaxis; pediatric guideline; short‐term prophylaxis.
© 2026 The Author(s). Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.