Hereditary angioedema
From IDWiki
Definition
- Congenital defect in C1 inhibitor (or C1 esterase inhibitor) causing recurrent episodes of angioedema potentially involving any mucosal surface
Classification
- Type I: abnormally low levels of normal serum C1 inhibitor
- Type II: normal levels of abnormal serum C1 inhibitor
- Type III: increased kininogenase activity (C1 inhibitor is normal)
Epidemiology
- 25% of cases are caused by do novo mutations
Clinical Presentation
- Recurrent episodes of angioedema (can involve any mucosal surface) without urticaria or pruritis
- May have a family history
Investigations
- Screening bloodwork in suspected cases:
- Complement component 4 (C4), which may be low
- C1 inhibitor (C1INH) antigenic levels
- C1INH functional levels
Management
- Acute
- Chronic
Further Reading
- Betschel S, et al. Canadian hereditary angioedema guideline. Allergy Asthma Clin Immunol. 2014;10(1):50.
- Cicardi M, et al. Classification, diagnosis, and approach to treatment for angioedema: consensus report from the Hereditary Angioedema International Working Group. Allergy. 2014;69(5):602-16.
