What is Hereditary Angioedema (HAE)?
Hereditary angioedema (HAE) is a rare genetic disorder characterized by episodes of swelling (edema attacks) in different areas of the skin or the internal organs. In particular, it occurs in the upper respiratory tract and intestine.(2,4)
Edema of the skin occurs mainly in the face (e.g. lips, eyelids), although the extremities and genitals are also often affected. In many cases, patients experience swelling and tightness of the skin or a tingling sensation, and in some cases pain. Although it is not life-threatening, people with this kind of edema often withdraw from their social lives because of the disfiguration caused.(4)
Edema of the mucous membranes of the larynx, nose or tongue is potentially life-threatening, as it can cause death by suffocation. Symptoms that are felt just before an attack in the throat may include difficulty swallowing, a hoarse voice, whistling or wheezing when breathing, a swollen tongue, cough, or shortness of breath. Patients who experience these symptoms and suspect the start of such an attack should seek emergency attention immediately. More than 50% of HAE patients will have at least one laryngeal edema in their lifetime.(4,8-10)
Abdominal pain is reported by 70-80% of patients with HAE.(2) This manifests itself primarily as loss of appetite, nausea, vomiting, diarrhea and abdominal cramps.(7) If HAE has not been diagnosed in these patients yet, suspicion of colic or appendicitis can lead to unnecessary surgical procedures or even to removal of healthy organs.(12)
It is estimated that about 1 in 10,000 to 1 in 50,000 people worldwide have HAE.(2,11) It occurs with roughly the same frequency in men and women.(14) Most patients experience their first attack during childhood or adolescence.(4)
The development of edema does not follow a typical pattern and therefore the site of the next episode of swelling cannot be predicted. The frequency, duration and severity of the edema vary considerably. Approximately a third of patients report more than one 1 attack per month; about 40% of patients experience on average 6-11 attacks per year and the remaining 22% only suffer attacks from time to time.(2) In most cases, the symptoms of HAE increase over 12 to 36 h and last for 2-5 days before resolving. However, some patients may experience attacks that last over a week.(2,7)
Most HAE attacks occur spontaneously, but patients can often link specific situations that occur in their lives, such as stress, infections or even the consumption of certain foods, to the development of edema.
The disorder places extraordinary strain on patients, often restricting their ability to lead normal lives. Untreated patients with HAE can lose 100 to 150 work days per year – if not more!