Hereditary Angioedema

What is Hereditary Angioedema?

Hereditary Angioedema or HAE is a rare but potentially life-threatening inherited condition which is characterised by spontaneous and recurring attacks of swelling (oedema) in various parts of the body. Attacks can be temporarily disfiguring, painful and sometimes life threatening when affecting the throat.

What are the signs and symptoms of Hereditary Angioedema?

HAE patients suffer from episodes of severe swelling involving the skin, respiratory and GI tracts. These attacks are very painful and can be life-threatening when swelling occurs in the airway.

What are the causes of Hereditary Angioedema?

HAE is caused by either the absence of a protein called C1 esterase inhibitor (C1-INH) or by a defect in the function of C1-INH. HAE attacks are meditated by bradykinin, a naturally occurring polypeptide. The increased levels of bradykinin lead to the oedema formation and swelling that is characteristic of HAE attacks.

Who is likely to be at risk of Hereditary Angioedema?

The prevalence of HAE has been estimated as about 10,000 to 50,000 people. In the majority of people with HAE, the disease is the result of C1-INH defects that are inherited. A parent with HAE has a 50% probability of passing the condition on to a child. In approximately 20% of cases, however, HAE is not inherited but instead results from new spontaneous mutation.

How is Hereditary Angioedema diagnosed?

Although HAE can be detected using a simple blood test, often the disease is misdiagnosed because many HAE symptoms are also associated with a range of common conditions such as allergies, colic, appendicitis, or other gastrointestinal illnesses. Diagnosis of HAE is often delayed, by as much as 10 or more years.

What are the treatments for Hereditary Angioedema?

Some patients may be given long-term treatment to reduce the number of attacks occurring (called prophylaxis). Short-term treatment to prevent attacks occurring (also called prophylaxis) is recommended for HAE patients undergoing dental procedures or surgery (which have been known to trigger attacks).

There are several therapies available for the treatment of acute attacks.