A new case study reports an 8-year-old girl with hereditary angioedema (HAE) with C1 inhibitor deficiency (C1-INH-HAE) was successfully treated with subcutaneous plasma-derived C1 inhibitor (pdC1INH; Berinert®).

Authors of the study, published in the Journal of Investigational Allergology and Clinical Immunology, noted that the special authorization required for this therapy significantly delayed this patient’s treatment, resulting in 13 attacks, 1 of which was life-threatening.

“Early onset may predict a severe course,” the authors wrote. “New approaches include subcutaneous pdC1INH, licensed for children over 6 years old in the United States but not until 12 years in Europe, and lanadelumab and berotralstat, not allowed in patients younger than 12 years.”

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The patient initially experienced 2 cutaneous angioedema attacks after ingesting ibuprofen. Challenge testing ruled out a hypersensitivity to ibuprofen and the attacks continued, so C1 inhibitor level was assessed and she was diagnosed with C1-INH-HAE. Screening demonstrated a family history of HAE.

The patient experienced multiple attacks despite long-term prophylaxis with tranexamic acid, requiring hospital visits, emergency room admissions, and subcutaneous icatibant treatment. In August 2020, her care team requested off-label authorization of pdC1INH, which was delayed until February 2021. In the meantime, she had 13 additional attacks, including 1 laryngeal episode that was life-threatening and required intravenous pdC1INH and hospital admission.

Long-term prophylaxis with 2000 IU of pdC1INH every 3 days resulted in the patient having 0 attacks and no further emergency room visits. One month after treatment initiation, her C1 inhibitor levels and function increased, and the frequency of treatment administration was reduced every 2 months thereafter following recommended guidelines.

She now takes pdC1INH on a 6-day schedule and has achieved complete disease control with no adverse events. The authors recommend studies on the validation of pediatric patient-reported outcome measures in HAE.


Lasa EM, Herrero L, Martínez S, Arruti N, Oliver P, Joral A. Use of concentrated plasma-derived subcutaneous C1 inhibitor as long-term prophylaxis in an 8-year-old child with hereditary angioedema. J Investig Allergol Clin Immunol. Published online August 24, 2022. doi:10.18176/jiaci.0855