BACKGROUND: There is a paucity of data that describe the clinical course of hereditary angioedema (HAE) in children. OBJECTIVE: The purpose of this study was to examine the clinical features of children with HAE. METHODS: Electronic medical records from the past 10 years at Cincinnati Children's Hospital Medical Center and an outpatient allergy community practice were searched for ICD-9 code 277.6 (Other deficiencies of circulating enzyme). Exclusion criteria included laboratory data not supportive of type I or II HAE diagnosis or age at diagnosis greater than 18 years. Chart review was performed and missing data were collected by telephone interviews with patient families. Descriptive statistics were performed using SAS version 9.4. RESULTS: Twenty-one children were identified. The median age was 13.2 years (interquartile range [IQR], 9.1-18.8), 71% were male, 86% had an HAE family history, and 95% were Caucasian. The median age of symptom onset and diagnosis was 5.7 (IQR, 5-9 years) and 5.0 (IQR, 4-8 years), respectively. Five children diagnosed were asymptomatic. Three children without a family history had a 6.0-year delay in diagnosis. The most common angioedema attack sites were abdominal, peripheral, and laryngeal, which occurred at least once in 93%, 73%, and 27%, respectively. Of the 15 children with onset of symptoms, only 6 children received on-demand therapy for an acute attack, whereas 13 children were administered either short-term or long-term prophylaxis therapy. CONCLUSIONS: In this pediatric HAE population, symptom onset and diagnosis occurred at a median age of 5 years with a delay in diagnosis in those without a family history. Abdominal attacks were more common than peripheral attacks in this population. (C) 2015 American Academy of Allergy, Asthma & Immunology