Food allergies and the symptoms that come along with them can be very disruptive and even dangerous. The best way to deal with a food allergy is to avoid the food you are allergic to (allergen). But how do you know what foods those are? There are scientific tests to help doctors figure out what foods if any are your allergens. You can read more about them in the article on diagnosing food allergies.
Food allergy testing can also be a hot topic for non-traditional doctors and others who may use a variety of unproven methods to try to diagnose a food allergy. Be wary of these tests that have not been scientifically proven to work and are often not covered by insurance:
• Cytoxic test – In this test, a bit of suspected food allergen is dried and placed on a microscope slide. A drop of your blood is added to the slide. The technician looks at the slide under a microscope to see if any white blood cells are “dying” on the slide as a result of being placed there with the allergen. This is an invalid test that is not based on scientific fact.
• Provocation test – In this test, small amounts of a suspected allergen are placed under your tongue (sublingual) or are injected under the skin (subcutaneous). The technician then asks if this has made your allergy symptoms worse. This has not been proven to be a valid way to diagnose a food allergy. An alternate version of this test, known as Provocation-Neutralization, starts the same with a small amount of allergen. If there is a reaction, the tester continues to give smaller doses of the allergen until the symptoms go away. This may sound similar to allergy shots, but is actually a different technique that has not been proven to either diagnose or cure food allergies.
• Electric current – In this test, you are asked to hold a class vial containing some of your suspected allergen in one hand. In the other hand, you hold something that is producing an electric current. A galvanometer, which is an instrument used to measure electric current, is inserted into the allergen in the vial you are holding. The galvanometer is supposed to read the amount of electric current flowing through your body with the allergen present. If the readings go down, meaning there is resistance to the current, the tester will claim you are allergic to whatever is in the vial. This is also an invalid test that does not work.
• Pulse – Some testers claim that if your pulse goes up, meaning your heart is beating faster, you are allergic to whatever you just ate. This test is not valid.
• Body Chemicals – This test measures the amount of certain toxins in your body. The testers claim that the build-up of toxins leads to allergy symptoms. The tests measure trace amounts, which means very, very small amounts of the toxins. There is no scientific evidence that these trace toxins are the cause of allergies.
• IgG Antibodies – This test measures the amount of Immunoglobulin G, which is an antibody produced by the immune system to fight infection. This is a real test of a real antibody. But the amount of IgG is not a valid predictor for food allergy. So while the test is valid in some cases, the use of the test to diagnose food allergies is not valid. A similar test for Immunoglobulin E (IgE) is a valid food allergy test.
Diagnosing food allergies can be a difficult and time consuming task that requires several tests. Your doctor can refer you to an Allergist who specializes in diagnosing and treating food allergies.
National Institute of Allergy and Infectious Diseases