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, according to DiscoverHAE.com. (1)
Making a HAE Diagnosis: Standard 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 C1 esterase inhibitor and C4. According to the U.S. Heriditary Angioedema Association (HAEA), the three blood tests used to confirm if you have HAE type 1 or type 2 include: (2)
C1-inhibitor quantitative (antigenic)C1-inhibitor functionalC4
Sometimes more than one of these tests is used to make a more precise diagnosis, according to an article published May 2016 in the journal Therapeutics and Clinical Risk Management. (3) Most doctors recommend waiting until children are at least 1 year old before testing their C1 inhibitor levels, notes the HAEA. (4) While there have been genetic tests to pinpoint these abnormalities, they were often time-consuming, expensive, and inaccurate. Also, because other undiscovered genes may play a role, a negative result might not completely rule out HAE. For these reasons, doctors typically recommend a diagnostic blood test to measure levels of the proteins C1 esterase inhibitor and C4 in the bloodstream instead of genetic testing. (5) However, in 2018, researchers discovered that a highly sensitive genetic test was better than traditional genetic tests for diagnosing type 1 and type 2 HAE. The new test screens for the entire SERPING1 gene and is now recommended as either the first-line or confirmatory method of genetic testing for patients. Scientists report it has an accuracy rate of 99.35 percent. (5) Some doctors might recommend genetic testing in children under 1 year old because they can get false results on standard blood tests. (3)
Misdiagnosis and Delayed Diagnosis Are Common Problems
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. (1) HAE is commonly mistaken for:
An allergic reactionAppendicitisIrritable bowel syndrome (IBS)
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. (1) 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. (1) 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, notes the HAEA. (6) 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. The HAEA offers a list of physicians around the country who treat HAE. Bring a copy of your test results and a list of questions with you to your first doctor’s appointment. A diagnosis of HAE can be scary, and you’ll probably have a lot of questions. Per the Cleveland Clinic, here are some questions to ask your doctor: (9)
What is HAE? Why do I have it?Do I need any more medical tests?How serious is this disease?What will my life be like with HAE?What symptoms should I watch out for?Are there any ways to prevent an HAE attack?What treatments are available?What are the treatment side effects?How often will I need to come to the doctor?Should my family members be tested for HAE?Where can I find support?
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.
