Hereditary angioedema (HAE) is an inherited disease characterized by recurrent episodes of severe swelling (angioedema).
Hereditary angioedema is estimated to affect 1 in 50,000 people.
The most common cause of HAE is a decrease in C1 esterase inhibitor (C1 INH), a protein that is part of our body’s normal immune system. Patients with HAE do not experience hives. Allergic reactions to foods or stinging insects, which may cause hives, may also cause angioedema.
This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In some cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family.
Symptoms include:
- Recurrent swelling in the arms, legs, abdomen, genitalia, face, or throat which is not usually painful
- Painful swelling of the bowel wall (the lining of the intestines) associated with nausea and vomiting
Symptoms of hereditary angioedema typically begin in childhood and worsen during puberty. On average, untreated individuals have an attack every 1 to 2 weeks, and most episodes last for about 3 to 4 days. The frequency and duration of attacks vary greatly among people with HAE, even among people in the same family.
Pressure, trauma, or emotional stress can trigger an attack; however, the trigger of most attacks is unknown. Typical attacks last for about 1-3 days. If your child develops an acute attack, please contact your physician or go to the emergency room.
Treatment for an attack includes:
- Cinryze, a new medication that contains CI INH, may be used to treat acute attacks
- Fresh frozen plasma may also be used to treat acute attacks
- New medications are currently being developed to help treat acute attacks for HAE
Attacks can be prevented with:
- Danazol, a type of steroid, is very useful for the prevention of an acute attack
- Cinryze, a new medication that contains CI INH
- Fresh frozen plasma has also been used successfully to prevent an attack prior to surgery or a dental procedure