Hereditary angioedema, also called HAE, is a rare genetic disorder that causes attacks of severe swelling. These attacks can occur anywhere in the body, but swelling in the face, genitals, the throat and the intestinal tract are also common. A number of patients also experience a non-itchy rash, either before or during an episode of swelling. Symptoms do not follow any consistent pattern and can be difficult to predict—the frequency of attacks can range from several times a month to only occasionally.
Who is at risk for HAE?
In most cases, hereditary angioedema is inherited from a parent—children of people who have HAE have a 50 percent chance of inheriting the gene mutation that causes HAE. However, in 25 percent of cases, the gene mutation is not inherited, but occurs spontaneously at conception. People who develop HAE because of this spontaneous mutation can pass it on to their children. With hereditary angioedema Type III, a very rare type of HAE, some people appear to be carriers of a gene that causes a different genetic mutation—though there is still much healthcare researchers do not understand about this type of HAE.
If you aren’t born with HAE, you cannot acquire it later in life. Most people experience symptoms in childhood, adolescence or as young adults. However, some people are not diagnosed with the condition until adulthood. If you suspect you have HAE, there are specific blood tests that can check for the condition—and it is important that you do so, since HAE attacks have the potential to be life threatening.
Have you ever had a blood transfusion or organ transplant before 1992?
What can increase the risk of an HAE attack?
As mentioned above, HAE attacks are inherently unpredictable and do not follow a pattern—in most cases, episodes occur without any identifiable catalyst. However, there are a number of things that are known triggers for an HAE attack. These include:
- Mental stress
- Physical exertion
- Surgery
- Dental work
- Minor traumas
- Illness (for example, the flu)
While you may not be able to predict when an HAE attack will occur, it is important to pay attention to potential triggers, as this may help you anticipate an attack.
Can HAE attacks be life threatening?
Attacks of hereditary angioedema can be life threatening, depending on where the swelling occurs. Swelling in the throat is the most dangerous type of attack, because it can cause asphyxiation—a potentially fatal event where swelling closes the airways, cutting off the supply of oxygen to the body. An estimated 50 percent of people with HAE experience at least one attack of swelling in the throat in their lifetime. Seek immediate medical attention at the first sign of throat swelling.
Attacks of swelling in the intestinal tract are also potentially fatal and require medical attention. Common symptoms of an HAE attack in the intestines are vomiting, diarrhea, abdominal pain and nausea. In severe cases, HAE attacks can cause hypovolemic shock, a condition where the body loses 20 percent or more of its fluid, which can result in organ failure and death.
What can you do to reduce your risk of attacks?
There is no cure for HAE, but there are a number of treatment options that can help you manage the condition, including oral medications, medications that are taken by injection and medications that are taken by infusion. Treatment goals focus on preventing attacks, reducing the number of attacks, reducing the severity of symptoms and halting and reversing attacks when they occur. Some medications are taken as preventive measures, while others are administered at the onset of symptoms. As healthcare experts learn more about HAE, more treatment options will become available.
Treatment plans are different for every patient. If you have HAE, it is important that you work with your healthcare provider to decide on a treatment plan that is right for you, and to receive training on how to administer the medications that you are prescribed.