Alternative Food Allergy Tests to Avoid
In 2010, the National Institutes of Health published the Guidelines for the Diagnosis and Management of Food Allergy in the United States.
Those guidelines say that the diagnosis of IgE-mediated food allergy should be based on a combination of:
- A careful history of the person’s experience with the suspected foods
- Skin prick testing
- Allergen-specific IgE blood testing (previously and commonly referred to as RAST or ImmunoCAP testing)
- Physician-supervised oral food challenge (the “gold standard” in food allergy testing)
These guidelines are based on proven scientific facts and studies. You can learn more about recommended food allergy testing by reading Dr. David Stukus’ article on “What Allergy Tests Mean.”
Here is where confusion starts. There are many other tests that claim to be accurate for providing “food allergy testing.” Some Internet sites and alternative medicine practitioners offer “food allergy tests.” Many of these tests claim to reveal “hidden allergies” that medical allergy tests cannot detect. These tests are not scientifically proven. They are not recommended for use in the diagnosis of food allergy.
The following is a brief description of 15 common types of alternative food allergy tests that you should avoid:
- ALCAT, ELISA, ACT and NuTron Tests. Each of these tests study changes to white blood cells that take allegedly take place in the presence of certain allergens. None of these delivers reliable results and do not have anything to do with detection of food allergies.There is zero scientific evidence to support using these tests for the diagnosis of food allergies.
- Applied Kinesiology or NAET Test (Nambudripad’s Allergy Elimination Technique). The idea behind kinesiology, or NAET testing, is that some foods can weaken your body by “blocking your energy fields.” These are not identical techniques, but in general, the practitioner tests changes in muscle strength in various ways while holding an allergen. For example, the practitioner might have the patient hold a container of milk in their left hand while the practitioner tests the strength of the patient’s right arm. Muscle weakness is thought to signal an allergy to the substance being tested.Practitioners then perform their “treatment” after identifying which allergens may be causing symptoms through invalidated and potentially dangerous methods.
- Basophil/Leukocyte Histamine Release Test. These tests measure whether certain blood cells are “activated,” as is seen in an allergic reaction. A blood cell is exposed to specific food allergens, and, depending on the type of test, researchers evaluate changes to the cells or histamine that is released from a blood sample when it is exposed to specific food allergens. The results of these tests can be difficult to interpret. Although these tests are being studied to diagnose clinically relevant food allergy, these remain experimental at this time.
- Cytotoxic Assay Tests. In this test, a blood sample is spun in a centrifuge (a lab instrument that separates substances of different densities) and then placed on a slide. The separated blood is exposed to different types of allergens. The blood is then looked at under a microscope after 10 minutes, 20 minutes, two hours and four hours to see if the cells change in shape. According to those who use this test, if the cells disappear, this indicates an allergy or sensitivity to the allergen. There is no scientific evidence to support cytotoxic testing for the diagnosis of food allergies.
- Electrodermal Test. In electrodermal testing, the skin is tested with various electrical currents and machinery resulting in a list of items to which you may be (reportedly) allergic or sensitive. There is no scientific evidence to support electrodermal testing for the diagnosis of food allergies.
- IgG Testing. In IgG testing, the blood is tested for IgG antibodies instead of being tested for IgE antibodies (i.e., the antibodies typically associated with food allergies). The existence of serum IgG antibodies towards particular foods is claimed by many practitioners as a tool to diagnose food allergy or intolerance. The problem with this is that IgG is a “memory antibody.” IgG signifies exposure to a food, not allergy to a food. Since a normal immune system should make IgG antibodies to foreign proteins, a positive IgG test to a food is a sign of a normal immune system. In fact, a positive result can actually indicate tolerance for the food, not intolerance. There is no scientific evidence to support IgG testing for the diagnosis of food allergies.
- Patch Test. In patch testing, the allergen is taped to the person’s back for 48 hours. The skin is then examined 72 and 96 hours after the patch is removed. Patch testing is used mainly for the diagnosis of contact dermatitis and delayed onset allergic reactions. The test has a very limited role in evaluating the impact of foods in eczema and eosinophilic esophagitis. The tests have not been standardized or validated for foods. The results are often quite variable (even for the same person over time), with a low predictive value. There is no scientific evidence to support patch testing for the diagnosis of immediate onset IgE-mediated food allergies.
- Provocation/Neutralization Test. In these tests, a small amount of the test substance is injected under the skin or placed under the tongue in an attempt to provoke symptoms. If symptoms do develop, then a larger dose is given, which will supposedly neutralize the first dose. Provocation/neutralization tests are used for vague, subjective complaints, such as fatigue and headaches. There is absolutely no role for this in food allergy testing, as it is not safe.Reacting to the first dose could certainly indicate an allergy. This is true especially if the allergen was placed under the tongue. This would, in effect be an oral food challenge. However, the larger dose would likely make the reaction worse, not neutralize it. There is no scientific evidence to support this test for the diagnosis of food allergies.
- Skin End-Point Titration Test. This is a form of intradermal testing. Increasing amounts of a diluted allergen solution are injected under the skin until a reaction occurs. For environmental allergies, the amount of allergen required to provoke the reaction is considered the “threshold” dose. This threshold dose is at which immunotherapy would be recommended. However, this test is not valid, particularly for food allergies, and often causes a lot of false positives and skin irritant reactions. Intradermal testing for food allergies should be avoided due to the potential to cause an allergic reaction.
- Lymphocyte Stimulation Test. This is a laboratory test for the identification of allergy to a specific drug.
- Facial Thermography Test. This is a non-invasive method to study the effects of antihistamine on the skin of the nose.
- Gastric Juice Analysis Test. This test has been studied for its usefulness in the diagnosis of food protein induced enterocolitis. For this test, the patient is challenged with some food, then a feeding tube is placed and some gastric juices are aspirated. The gastric juices are tested for specific markers.
- Endoscopic Allergen Provocation Test. Also known as colonoscopic allergen provocation test (COLAP), this test is performed by endoscopy. The doctor introduces an allergen, such as birch pollen, into the colon. The mucus membrane is then examined for an allergic response and biopsies are taken.
- Hair Analysis Testing. This is a test in which a sample of a person’s hair is sent to a laboratory for measurement of its mineral content.
- Mediator Release Assay.This is a blood test to measure mediator release that is used to assess inflammatory response to food and food chemicals.
Kids with Food Allergies recommends seeing board-certified allergists who use scientifically proven tests, as described in the Guidelines for the Diagnosis and Management of Food Allergy in the United States. Discuss with your allergist your best treatment options and prevention strategies, and understand how to handle severe allergic reactions with epinephrine. Do not refer to any of the above types of tests for diagnosing IgE-mediated food allergy.
Medical review: April 2015.