What Is Hereditary Angioedema (HAE)?

About HAE

About HAE

Hereditary angioedema, or HAE, is a rare disease, affecting an estimated 1 in 10,000 to 1 in 50,000 people around the world. HAE can cause attacks of sometimes painful and disabling swelling in the abdomen, face, feet, genitals, hands, and throat.

Defining HAE

HAE is called "hereditary" because literature suggests that about 75% of cases are passed down through families. Still, about 25% of people with HAE have no family history at all. These cases result from a genetic change that happens spontaneously. Once the spontaneous change happens, it can be passed on to children.

HAE attacks often happen without a known trigger. However, they can sometimes be triggered by:

• Minor trauma (an injury or shock to the body)
• Stress
• Dental procedures
• Infections
• Surgery
• Hormonal changes

During an HAE Attack

A protein called plasma kallikrein triggers the production of another protein called bradykinin that may lead to HAE attack symptoms.

• Your body's levels of activated plasma kallikrein are increased.
• The increased levels of plasma kallikrein lead to the formation of bradykinin that causes blood vessels to release fluid.
• Released fluid builds up in various parts of the body, resulting in localized swelling and pain.

Common HAE symptoms include sometimes painful swelling. Swelling in the throat can make breathing difficult, and about 50% of people in a survey of 209 patients experienced at least 1 throat attack.

When untreated, the swelling in an HAE attack usually increases over a 24-hour period and then gradually subsides during the next 48–72 hours. Some people experience attacks that last longer than a week. An HAE attack can also start in one location and then spread to another before resolving.

Treatment Options

Two types of HAE treatments are currently available: preventive and acute.

• Preventive treatment, also called prophylactic treatment, or prophylaxis, is taken on a regular basis to prevent or reduce the number of HAE attacks. Current guidelines recommend that all patients should be evaluated for long-term preventive treatment at every doctor's visit, or at least once a year.
• Acute treatment, also known as on-demand treatment, is used to treat the symptoms of an HAE attack.
• Even with preventive treatment, attacks can happen. Experts recommend that acute treatment be a part of every HAE treatment plan.
• Treatment of acute HAE attacks should be administered as early as possible in an attack, for all attacks, regardless of location, as soon as they are clearly recognized.

Learn how KALBITOR (ecallantide) works to treat HAE attacks by inhibiting plasma kallikrein.