Hereditary Angioedema
Hereditary angioedema (HAE) is a rare inherited condition in which recurring episodes of swelling occur beneath the skin and in body cavities. Unlike allergic swelling, HAE attacks are triggered by low or dysfunctional levels of a protein called C1-inhibitor, and they do not respond to antihistamines or adrenaline. Episodes can last two to four days and, when the throat is involved, become life-threatening.
Key points
- Attacks are driven by low or faulty C1-inhibitor protein levels and, unlike allergic swelling, do not improve with antihistamines or adrenaline.
- Individual episodes typically run two to four days in length, and involvement of the throat turns the episode life-threatening.
- Danazol, a synthetic hormone, has long been used to raise C1-inhibitor activity and cut how often attacks occur, dosed at the lowest level that works.
Keeping attacks under control
Long-term management aims to reduce how often attacks occur and how severe they are. Danazol, a synthetic hormone, has been used for decades to raise C1-inhibitor activity and lower attack frequency. Because danazol acts on hormone pathways, it sits within women’s health medicine more broadly, and dosing is usually kept at the lowest effective level to limit side effects.
Anyone with HAE should have a clear action plan agreed with a specialist, carry acute treatment at all times, and seek emergency care immediately if throat swelling develops.