Hereditary angioedema is a rare but serious problem with the immune system that is passed down through families. It causes swelling, particularly of the face and airways, and abdominal cramping.
Causes, incidence, and risk factors
Hereditary angioedema (HAE) is caused by low levels or improper function of a protein called C1 inhibitor. This problem affects the blood vessels. People with hereditary angioedema can develop 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. However, 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 have been shown to trigger certain attacks of hereditary angioedema.
- Airway blockage — involves throat swelling and sudden hoarseness
- Repeat episodes of abdominal cramping without obvious cause
- Swelling in the arms, legs, lips, eyes, tongue, or throat
- Swelling of the intestines — can be severe and lead to abdominal cramping, vomiting, dehydration, diarrhea, pain, and occasionally shock
There is usually no itching or hives.
Signs and tests
Blood tests (ideally done during an episode):
Antihistamines and other treatments used for angioedema are of limited benefit in hereditary angioedema. Epinephrine should be used in life-threatening reactions.
The most effective treatment is a C1 inhibitor concentrate, but this may not be available. Fresh frozen plasma contains C1 inhibitor and will help an episode, but rarely, the swelling will become worse.
Attenuated androgens, such as danazol, can reduce the frequency and severity of attacks by increasing the production of C1 inhibitor.
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. Getting rid of the bacteria with antibiotic therapy decreases these abdominal attacks.
Hereditary angioedema can be life threatening and treatment options are limited. How well a person does depends on the specific symptoms.
~ Info from MedLine