Because HAE is so rare, many doctors aren’t familiar with the disease. Also, your symptoms can mimic those of other conditions, which further complicates the process.
To receive an HAE diagnosis, you’ll need to have a physical exam as well as blood tests.
If your doctor thinks you might have HAE, he or she will probably first ask about your symptoms and family history. It’s important to know that you could have HAE even if your family members don’t.
The next step is to perform lab tests to measure levels of the proteins C4, C1 esterase inhibitor, and C1 esterase functional level.
The three blood tests used to confirm if you have HAE type 1 or type 2 are:
C1-inhibitor quantitative (antigenic)
C1-inhibitor functional
C4
Sometimes more than one of these tests is used to make a more precise diagnosis.
Most doctors recommend waiting until children are at least 1 year old before testing their C1 inhibitor levels.
Most cases of HAE type 1 and 2 are caused by a gene mutation that affects the SERPING1 gene, while HAE type 3 is affected by genes F12, PLG, ANGPT1, and KNG1. However, genetic testing is not a simple process for this disease.
Genetic testing does not always give clear answers, but it is more reliable in detecting the most common forms of the disease involving HAE-1 or HAE-2. And it can detect certain mutations that standard testing can miss. It offers less in confirming rare cases with normal C1-inhibitor levels.
Genetic testing cannot predict disease progression or severity. And a recent study showed that while most doctors think genetic testing would help, barriers to using it include insurance, cost, and the availability of genetic counseling to interpret the tests.
Some doctors might recommend genetic testing in children under 1 year old because they can get false results on standard blood tests.
People with HAE are often misdiagnosed as having another medical problem. In one survey of 313 patients, 65 percent of those with HAE reported being misdiagnosed before a doctor accurately identified their condition.
In the past, HAE diagnosis delays ranged from 10 to 22 years. Today, about 40 percent of people with HAE are diagnosed within the first three years. About 33 percent of people still face delays of 10 years or longer.
A misdiagnosis or delayed diagnosis can lead to serious consequences because people with HAE may not receive the proper treatment that can help their condition. About 19 percent of people also undergo unnecessary medical procedures, including appendix removal, because of a misdiagnosis.
In the most extreme cases, a missed diagnosis can be deadly. In studies, death rates from an HAE throat swelling episode can be as high as 30 percent if patients don’t receive treatment.
The age of onset for people with HAE varies. Studies show that about one-half report their first symptoms by age 7, and more than 66 percent have symptoms by age 13.
Typically, the number and severity of attacks increase during a person’s teenage years.
Because many people with HAE experience diagnosis delays, symptoms can start long before an official diagnosis is made.
If you receive an HAE diagnosis, you may want to recommend that your close family members get tested, too, since HAE can run in families.
Once you’re diagnosed, it’s important to find a doctor who has experience treating the disease. You can find a specialist by contacting advocacy organizations or experts who appear in published medical journals. Board-certified allergists and immunologists are trained to manage and treat patients of all ages with HAE.The U.S Hereditary Angioedema Association offers a list of physicians around the country who treat HAE.
A diagnosis of HAE can be scary, and you’ll probably have a lot of questions. So along with a copy of your test results, bring a list of questions to your first doctor’s appointment.
Per Cleveland Clinic, here are some questions to ask your doctor:
Taking charge of your health is important. Make sure you’re comfortable talking to your doctor about your condition and all available treatment options. If you don’t feel like your provider is a good fit, try making an appointment with another specialist.
Blood tests are the standard method for determining an HAE diagnosis, but genetic testing is becoming more established.
Misdiagnosing HAE for gastrointestinal issues, allergic reaction, or appendicitis is common and can lead to serious consequences. Some patients undergo unnecessary treatments or surgeries because of a misdiagnosis.
After a diagnosis, find a doctor experienced in treating the disease.
It’s also important to alert immediate family members to give them the option to get tested, even if they are asymptomatic.
