If you deal with allergies, you know it’s not always easy to figure out what’s causing an adverse reaction. But is a home allergy test the best way to pin that down?
Probably not, says allergist/immunologist Lily Pien, MD, MHPE.
Millions of Americans wrestle with allergies based on the season, exposure to pets or dust, or specific foods. Treatment depends on how severe your symptoms are and which allergy triggers (allergens) are involved.
Dr. Pien explains three main reasons why home allergy tests are not the best tool for pinpointing your problem.
1. You may not get accurate results
“A true allergy is defined as experiencing allergic symptoms after exposure to a known allergen,” Dr. Pien says. Either a skin test or a blood test can help to pinpoint the cause by looking for specific immunoglobulin E (IgE) antibodies.
What home allergy kits are testing for is not always clear. For example, some kits do not test for specific IgE antibodies, so their results may not reflect an actual allergy.
Some home tests may measure immunoglobulin G (IgG) antibodies instead of IgE antibodies to foods. “This type of testing does not reveal a true food allergy. It may cause significant harm by forcing people to avoid foods, making them believe they are allergic to several foods when they are not,” she says.
In addition, some home allergy tests may have you send in a hair sample instead of a blood sample. “Because there is no IgE in hair, results are not going to reflect a true food allergy,” Dr. Pien says.
2. You may be intolerant vs. allergic to food
If you notice that a certain food bothers you, you may assume you’re allergic to it. But there’s a big difference between food allergies and intolerance:
- Food allergies engage your immune system. They can cause an immediate and possibly life-threatening reaction requiring immediate treatment with life-saving medication.
- A food intolerance affects your digestive symptom and can lead to cramping or diarrhea (lactose intolerance is an example).
“If you want to know whether you have IgE-mediated food allergies, you need to have a skin test or blood test measuring specific IgE response to that food,” Dr. Pien advises. Food challenges are sometimes performed to help with the diagnosis.
And, when it comes to environmental factors such as pollen or dust, you may believe you have an allergy because your eyes are red and itchy. But you could have an eye infection.
The treatments are different for allergies and infections. “You may end up treating an incorrect diagnosis or the wrong thing unless you work with your doctor to find out exactly what’s causing your eye problems,” she says.
3. You need expert interpretation of the results
If you use a home allergy test, understanding the results can be difficult. Your doctor can help and should be involved. “Medical tests are best interpreted by consulting a healthcare provider,” Dr. Pien says.
That means you’ll need to see your doctor and may have to have additional tests done at the doctor’s office.
Even if your home test identifies a true allergen, it’s best to work with your doctor to treat your allergy.
Still going ahead with home tests?
If you decide to proceed with home testing, ask your doctor’s advice about specific products before your spend your money, Dr. Pien says. There are lots of home allergy tests on the market, and their quality varies.
Ultimately, you’ll get the best results and treatment advice from a board-certified or board-eligible allergist. “They will know which tests are appropriate for you, and will accurately interpret the results,” she says.