what is hereditary angioedema?
Hereditary angioedema (HAE) is a rare genetic disorder. It's thought that only 1 in 10,000 to 1 in 50,000 people in the entire world have HAE.
signs and symptoms of hereditary angioedema
HAE can cause painful and sudden swelling in any part of the body. These HAE “attacks” can happen without warning and last for days. The pain and swelling of an attack can also be disabling, making it difficult to perform everyday tasks. This can make living with HAE physically and emotionally challenging.
Attacks can occur in any part of the body, but common swell locations include:
- Throat - Genitals
Swelling in the throat can become life threatening because it can lead to suffocation. If you have an attack affecting the throat, you should seek emergency care right away.
HAE can be unpredictable
HAE symptoms can look very different from person to person—and even within the same person. For instance, someone with HAE may get attacks more often during puberty. Or someone who usually experiences abdominal swelling may still have an attack in the throat or elsewhere.
good to know
An HAE attack can start in one location and spread to another.
HAE attacks may last for days if not treated. The swelling usually gets worse over a 24-hour period and then slowly goes away during the next 48–72 hours.
Some people experience a tingling sensation before an attack. They may also notice a nonraised, non-itchy rash before the swelling begins.
what causes hereditary angioedema?
Many people with HAE have low levels of an important protein called C1 esterase inhibitor (C1-INH) in their blood—or this protein doesn't work the way it should.
When there isn’t enough working C1-INH, another protein called plasma kallikrein becomes overactive. Too much plasma kallikrein activity leads to an overproduction of bradykinin— substance that leads to an attack.
What causes HAE attacks?
HAE attacks are sometimes set off by a trigger. HAE can vary a lot from person to person, so your triggers might be very different from someone else’s. For example, some people might only experience an HAE attack because they've gone through a physical trauma, like falling off a bicycle or having a dental procedure. For others, something as simple as making a repetitive motion, like using scissors, could cause an HAE attack.
Some common triggers are:
- Emotional stress
- Minor injury, surgery, or dental procedure
- Hormonal influences, like menstruation or certain types of birth control
- Physical activities like mowing the lawn or using scissors
how is hereditary angioedema diagnosed?
Getting a diagnosis starts by talking with your doctor. Because HAE is rare, few people have heard of it, including many doctors. In fact, many doctors will never see a patient with HAE. That's why getting an accurate diagnosis can be challenging.
What to expect at your doctor's appointment
If your doctor thinks you might have HAE, he or she will likely ask about your symptoms and when you first noticed them. Because HAE is usually passed down through relatives, your doctor will probably also ask if anyone in your family has swelling episodes or has been diagnosed with HAE.
good to know
You could still have HAE even if no one else in your family has it. One in four HAE cases results from a spontaneous genetic mutation.
Use this guide to start a conversation with your doctor about HAE and your symptomsdownload
Tests to confirm a diagnosis
If your doctor thinks you might have HAE, a blood test is often used to confirm the diagnosis. This measures how much C1-INH protein you have. They will also look at other information, like your symptoms, how they respond to certain medications, and your family history.
how is hereditary angioedema treated?
When talking with your doctor, it might be helpful to ask about different treatment options for HAE. These options include preventive and on-demand therapy.
Preventive HAE treatment is also called prophylactic treatment. This involves taking medicine routinely to help you have fewer attacks and less severe attacks.
On-demand HAE treatment is medicine used to treat the symptoms of an HAE attack. It is also known as acute treatment.
Not every person with HAE will have an attack that affects the airway, but it is a risk. These attacks can be life threatening, so leading health organizations recommend that everyone with HAE have access to on-demand therapy. If you have HAE, it's important to talk with your doctor about on-demand treatment.
good to know
Because HAE can affect people so differently, it's important to work closely with your doctor to create a treatment plan that's right for you.