Symptoms of HAE usually start in childhood and worsen during the teen years, according to the U.S. Hereditary Angioedema Association (HAEA). (1) People with HAE may notice that their hands, feet, face, and throat swell up. Abdominal pain, nausea, and vomiting are also common symptoms if HAE affects a person’s intestinal tract, notes Discover HAE. (2) Although HAE is a lifelong disease, there are treatments to help manage the condition.
Why Does Hereditary Angioedema Happen?
HAE is caused by a mutation, or defect, in the gene that makes a protein called C1 inhibitor. This protein helps control inflammation in your body. (1,2) These mutations are inherited in an “autosomal dominant” pattern, meaning that it takes inheriting only one copy of the gene from a parent to have the disease, according to Genetic and Rare Diseases Information Center. (3) If one parent has the gene defect that causes HAE, a child has a fifty-fifty chance of inheriting it notes the HAEA. (4) In most cases of HAE, the gene mutations mean that you either don’t have enough C1 inhibitor, or it doesn’t function properly, according to the American Academy of Allergy, Asthma, and Immunology. (5) Not having a family history doesn’t guarantee you won’t develop HAE. The genetic mutations that cause HAE can also crop up for unknown reasons during conception. In fact, as many as 25 percent of HAE cases result from a spontaneous gene mutation. (2) HAE attacks cause swelling in different parts of the body. Attacks can range from mild to severe. The frequency and length of the swelling attacks varies in those with HAE. Typically, people who aren’t receiving preventive treatment for the disease have an attack about every one to two weeks. Most of these episodes last three to four days. (1) Your symptoms will depend on the type of HAE attack you have. A subcutaneous attack involves swelling and redness on different areas of your skin. If you have an abdominal episode, you might experience stomach pain, nausea, diarrhea, or vomiting. Swelling attacks that involve the face, throat, neck, or tongue are particularly dangerous because they can interfere with breathing. These episodes are usually considered medical emergencies. You may need a breathing tube placed down your throat or into your windpipe to open your airways. Sometimes severe swelling in your throat can even lead to death. (2,6)
What Are the Triggers of an HAE Attack?
Sometimes, people with HAE are able to identify certain triggers that spark the swelling. Other times, these attacks come without warning. Per the HAEA, common triggers of HAE attacks include: (7)
AnxietyStressMinor traumaSurgeryAilments such as colds or flu
It’s important to identify the first signs of an HAE episode, so you can get treatment quickly. Learn More About Signs and Symptoms of Hereditary Angioedema
There Are Three Types of HAE
HAE only occurs in about 1 in 10,000 to 1 in 50,000 people worldwide. (2) The three main types are: (1)
Type 1 This is the most common form of HAE. People with type 1 have low C1 inhibitor levels. Type 1 accounts for about 85 percent of all cases.Type 2 With this type, C1 inhibitor levels are normal, but the protein doesn’t work like it should. About 15 percent of occurrences are type 2.Type 3 In this ultrarare form of HAE, C1 inhibitor levels and function are normal. Some instances of type 3 HAE may be due to mutations in the F12 gene, but doctors aren’t sure what causes other cases. (6) Type 3 was once thought to occur only in women, but scientists now know men are also affected. It’s usually diagnosed in adulthood. Type 3 HAE is so rare that scientists aren’t sure exactly how many people have it. (1)
Each type of HAE produces similar episodes of swelling. Other related disorders can cause similar symptoms. These may include: (8,9)
Acquired Angioedema (AAE) This type of angioedema isn’t hereditary but causes swelling episodes that are similar to those of HAE. AAE is sometimes linked to an underlying medical condition, such as an autoimmune disorder.Drug-Induced Angioedema Some medicines can cause angioedema attacks, even if you’re not allergic to the drug. Common culprits include angiotensin-converting enzyme (ACE) inhibitors, ibuprofen, and angiotensin-2 receptor blockers (ARBs).Cutis Laxa This is a rare, inherited disorder that causes limp, saggy, inelastic skin. It’s often confused with HAE.
In one study, one-half of the participants said their symptoms started by age 7. More than two-thirds said they had symptoms by age 15. Many people report experiencing more attacks around the time of puberty or adolescence. Research shows that because HAE is rare and often confused with other disorders, about 33 percent of people with HAE face diagnosis delays of 10 years or longer, according to Discover HAE. (10) Most experts recommend that, if HAE is known to run in a family, parents wait until a child is at least 1 year old before testing them for the disease. (4) If you have hereditary angioedema (HAE), getting an accurate diagnosis might be an uphill battle. Many people go years without being diagnosed. Others are mistakenly told they have another condition. A misdiagnosis can be inconvenient and dangerous. You might not get the correct treatment, or you may have to undergo unnecessary medical procedures. A simple blood test can usually detect HAE. Genetic testing is another method, but it’s usually not the preferred option for most people. Once you do get a correct diagnosis, it’s important to find a specialist who has experience working with HAE patients. Learn More About Hereditary Angioedema Diagnosis Your doctor will recommend a treatment plan based on how often you have HAE attacks, how severe the attacks are, your general health, and other factors. All HAE patients should have access to an on-demand treatment to take when they have symptoms. Your doctor might also prescribe a preventive medicine to help protect against a future attack. There are seven FDA-approved therapies to prevent or treat HAE. Medication like antihistamines or steroids — which are typically used to treat allergic reactions — generally won’t help an HAE episode. Your healthcare provider can assist you in deciding on the best treatment regimen for your disease. Some people with HAE are interested in clinical trials, which may provide a new treatment option that isn’t yet available to the general public. You can search for clinical trials at the ClincalTrials.gov website. Learn More About Hereditary Angioedema Treatment It’s a good idea to keep a journal listing any potential triggers that could be causing your attacks. Family members and close friends should know what to do if you experience an episode. Keep your medical paperwork with you in case you have a severe attack and can’t help yourself. The U.S. HAE Medical Advisory Board also recommends that all patients keep a record of their attacks, the medicines they use, and how they respond to treatment. (11) Learn More About the Triggers of Hereditary Angioedema Your long-term outlook will depend on the frequency, severity, and location of your HAE attacks. About one-third of people with HAE report having more than one attack per month. Roughly 40 percent have an average of 6 to 11 attacks per year. About 22 percent only experience attacks from time to time. Some people report attacks that last more than a week. (5) Typically, swelling episodes continue throughout a person’s lifetime, but they can be controlled with certain treatments. (6) If you have HAE, it’s important to find a doctor who’s experienced in treating the disease. Immunologists and hematologists are often trained to help people with HAE. (5) Living with HAE can be overwhelming at times. Unpredictable attacks often interfere with your professional and social life. If untreated, some attacks can last longer than a week. Many people with HAE miss out on school, work, and other activities. The good news is there are steps you can take to help cope with your disease. Creating a support system, lowering your stress levels, and connecting with a patient advocate are just some ways to take charge of your illness. You’ll probably still be able to experience other life events, like pregnancy and traveling, but you might need to take special precautions. People with HAE can live productive and fulfilling lives. Having a plan in place can help you achieve success. Learn More About Living With Hereditary Angioedema Learn More About Resources for Coping With Hereditary Angioedema
