Hereditary Angioedema (HAE)



Hereditary angioedema is a rare but serious problem with the immune system. The problem is passed down through families. It causes swelling, particularly of the face and airways, and abdominal cramping

Commonly Associated With

Quincke disease; HAE – Hereditary angioedema; Kallikrein inhibitor – HAE; Bradykinin receptor antagonist – HAE; C1-inhibitors – HAE; Hives – HAE


Angioedema is swelling that is similar to hives, but the swelling is under the skin instead of on the surface.

Hereditary angioedema (HAE) is caused by a low level or improper function of a protein called the C1 inhibitor. It affects the blood vessels. An HAE attack can result in rapid swelling of the hands, feet, limbs, face, intestinal tract, larynx (voicebox), or trachea (windpipe).

Attacks of swelling can become more severe in late childhood and adolescence.

There is usually a family history of the condition. But relatives may be unaware of previous cases, which may have been reported as an unexpected, sudden, and premature death of a parent, aunt, uncle, or grandparent.

Dental procedures, sickness (including colds and the flu), and surgery may trigger HAE attacks.


Symptoms include:

  • Airway blockage — involves throat swelling and sudden hoarseness
  • Repeat episodes of abdominal cramping without an obvious cause
  • Swelling in the hands, arms, legs, lips, eyes, tongue, throat, or genitals
  • Swelling of the intestines — can be severe and lead to abdominal cramping, vomiting, dehydration, diarrhea, pain, and occasionally shock
  • A non-itchy, red rash

Exams & Tests

Blood tests (ideally done during an episode):

  • C1 inhibitor function
  • C1 inhibitor level
  • Complement component 4


Antihistamines and other treatments used for angioedema do not work well for HAE. Epinephrine should be used in life-threatening reactions. There are a number of newer FDA-approved treatments for HAE.

Some are given through a vein (IV) and can be used at home. Others are given as an injection under the skin by the patient.

Choice of which agent may be based on the age of the person and where the symptoms occur.

Names of new drugs for the treatment of HAE include Cinryze, Berinert, Ruconest, Kalbitor, and Firazyr.

Before these newer medicines became available, androgen medicines, such as danazol, were used to reduce the frequency and severity of attacks. These medicines help the body make more C1 inhibitors. However, many women have serious side effects from these medicines. They can also not be used in children.

Once an attack occurs, treatment includes pain relief and fluids given through a vein by an intravenous (IV) line.

Helicobacter pylori, a type of bacteria found in the stomach, can trigger abdominal attacks. Antibiotics to treat the bacteria help decrease abdominal attacks.


Courtesy of MedlinePlus from the National Library of Medicine