- About This Section
- We review home test kits the same way we would explain them to someone at a meeting: plainly, and including the ones not worth buying.
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Two boxes sit on the same virtual shelf, sold by the same company, at roughly the same price. One measures something an allergist would also measure. The other measures something allergists have spent years asking people to stop paying for. Nothing on the packaging makes it obvious which is which, so that distinction is most of what this guide is about.
An allergy test worth taking measures IgE, the antibody your immune system produces when it treats something harmless as a threat. That is the mechanism behind hay fever, cat allergies and true food allergy. Real clinics measure it, home kits measure it, and the numbers mean roughly the same thing in both places.
The other category is sold as a food sensitivity test and measures IgG. IgG to food is not a malfunction. It is a record of what you have eaten. Most people carry IgG antibodies to the foods they eat most often, which is why these panels so reliably flag wheat, dairy and eggs for people whose diets contain wheat, dairy and eggs. The American Academy of Allergy, Asthma and Immunology puts it on their Choosing Wisely list, advising clinicians not to order IgG testing to evaluate allergy. We are not going to soften that. If a kit says food sensitivity and IgG, put it down.
A dozen foods come back highlighted, so you cut them out. Some symptoms improve, because cutting out most of what you eat usually changes how you feel for a few weeks. Then the list of safe foods keeps shrinking, and now there is a real problem: a narrowed diet, possible nutrient gaps, and a belief about your body that came from a test that was never measuring what you thought.
With children this gets worse. Unnecessary elimination diets in kids carry documented nutritional risk, and avoiding a food a child is not actually allergic to can raise the odds of developing a genuine allergy to it later. If a parent is going to remove a major food group from a child’s diet, that decision belongs with a pediatrician, not a mail-in panel.
Environmental allergens. If you are congested for eight months a year and cannot tell whether the culprit is the cat, the carpet or April, an indoor and outdoor IgE panel gives you something to act on. Dust mite positive means mattress and pillow covers and hot washes. Tree pollen positive means starting an antihistamine a couple of weeks before the season rather than after it flattens you. Cat positive means a conversation you were probably avoiding.
These answers are worth having because they change specific behaviour, and none of the actions they point to are risky. That is the honest test for any home kit: does the result change what you do, and is the resulting action safe to take on your own?
This is the part that catches people. A positive IgE means you are sensitized: your immune system has made antibodies to that thing. Plenty of people are sensitized to foods they eat with no trouble at all. Sensitization is a finding. Allergy is a diagnosis, and it takes the finding plus an actual history of reactions, which is why the definitive test for food allergy is still a supervised oral food challenge in a clinic with a crash cart nearby.
Read the number as a question to bring to a doctor rather than an answer you already have.
Celiac disease is not an allergy and does not show up on either panel above. The screening blood test is tissue transglutaminase IgA, and home versions exist. The trap: the test only works if you are currently eating gluten. Cut gluten out for a month, then test, and you can get a clean result while still having celiac disease. People do this constantly and then spend years unsure. If you suspect celiac, test first and change your diet afterward.
Same standard as the rest of this section, including our guide to what home test accuracy actually means: screen at home when the answer is useful and the next step is safe, and hand anything serious to a professional.