HAE is a rare, serious, and potentially life threatening genetic disorder. It causes repeated episodes of spontaneous swelling that can occur in almost any part of the body. However, the swelling usually occurs in the hands, feet, face, throat, and internal organs. HAE is not an allergy of allergic reaction.

HAE is a rare disorder that affects between 1 in 50,0000 and 1 in 150,000 people.

HAE is an autosomal dominant inheritable genetic disease caused by a deficiency in the blood protein C1 esterase inhibitor (C1-INH). C1 INH levels can be low but function normally (type 1 HAE) or be at normal levels, but the function is impaired (type 2 HAE). In very rare cases, levels of C1-INH can be normal and the blood protein can function normally (HAE with normal functioning C1-INH).

Early signs include fatigue, rash, nausea, stomach cramps or an upset stomach, and headache. Symptoms include swelling of the upper airway/throat, face, hands, feet, or genitals, pain in the abdomen (belly), muscle and joint pain, numbness, or tingling.

HAE is diagnosed by taking a blood test. Levels of the blood proteins C1-INH and C4 are often assessed by screening tests.

HAE is not contagious. As HAE is an autosomal dominant inheritable disease, if one parent has HAE, the chance of their children inheriting HAE is 50%. If you have no family history of HAE, but are diagnosed with HAE, you could pass the spontaneous mutation in the C1-inhibitor gene on to your children.

HAE has no effect on fertility.

The age at which children should be tested for HAE is a matter of personal choice for the family. Routine blood tests can be done from the age of 1 year. However, genetic testing may be done on blood taken from umbilical cord at birth.

A child with HAE will benefit greatly from being encouraged to have a positive attitude to cope with their condition, as well as to fulfil their ambitions and dreams. An individual HAE management plan may be put in place.

If you or someone you know is diagnosed with HAE, travelling is still possible. See our 5 top tips for travelling.

There is a wealth of resources available for you. View the support and resources here.