About Our Basic Food Allergy Test
Purpose of the test
Food allergies and food intolerances are different conditions with different testing methods. Clinical allergy testing (often measuring IgE antibodies or skin responses) is validated to identify food allergies. Some intolerances, like lactose intolerance, can also be diagnosed with specific breath tests. At present, no broad laboratory test can reliably diagnose most food sensitivities or intolerances.
That being said, if you have experienced symptoms of a potential problem, you can discuss gluten and lactose intolerance testing with your doctor.
What does our basic food allergy test measure?
Tests are typically tailored to match your symptoms and health history.
Because there can be symptom overlap between food sensitivities and food allergies, the doctor may recommend a skin prick test or blood allergy test to be sure that you don’t have a food allergy.
Unfortunately, tests cannot easily identify most food sensitivities. However, some specific intolerances can be found with testing:
- Lactose intolerance, which is the inability to properly digest a type of sugar found in milk products, can be detected with lactose tolerance tests. These include blood or breath tests that demonstrate disrupted lactose digestion.
- Celiac disease is a disorder in which a person’s immune system attacks their intestinal lining when they consume gluten, a protein found in wheat and other grains. Blood tests can help diagnose celiac disease by analyzing levels of specific antibodies, which are proteins produced by the immune system.
Some people are intolerant of gluten without having celiac disease, and this is often referred to as non-celiac gluten sensitivity (NCGS). There is no test that has been validated to accurately detect NCGS.
For most other food intolerances and sensitivities, there is no reliable test to detect them. As a result, a doctor may suggest other types of tests:
- Oral food challenge: This involves eating increasing quantities of a food over a period of hours while being closely monitored for adverse reactions. Oral food challenges follow a specific protocol and should only be done in a controlled medical setting.
- Food elimination diet: This requires following a strict diet that excludes specific foods or additives for a period of weeks. Over time, the dietary restrictions may be modified to try to identify specific intolerances or sensitivities.
People with symptoms of food reactions may have testing for other conditions such as inflammatory bowel disease, irritable bowel syndrome, or malabsorption of nutrients. Examples of tests related to these conditions are listed in the table below:
| Test Name | Test Sample | What It Measures |
|---|---|---|
| Xylose Absorption | Blood and urine | How well the body absorbs a simple sugar |
| Fecal fat | Stool | Amount of fat in a stool sample |
| Erythrocyte Sedimentation Rate (ESR) | Blood | Rate at which certain red blood cells fall when blood is placed in a test tube |
Many tests that are marketed for detecting food sensitivities and intolerances have not been proven to be accurate or effective, and experts recommend against using them. Examples of unvalidated tests include:
- Immunoglobulin-G (IgG and IgG4) antibody tests
- Hair tests
- Blood cell analysis, including flow cytometry and mediator release tests
- Provocation or neutralization testing
- Electrodermal testing
- Muscle reaction or strength tests
When should I get a basic food allergy test?
It is generally recommended to only test for food sensitivities or intolerances after you have experienced symptoms of a potential problem. If you’ve had signs of a food reaction, talk with your doctor. By reviewing your experience and symptoms, the doctor can describe the pros and cons of testing for specific allergens, intolerances, and/or sensitivities.
The downside of testing for a wide range of possible reactions is that it can return a false positive, which means the test shows an intolerance or sensitivity for a food that doesn’t actually cause you problems. False positives can cause unnecessary changes to your diet that may affect your nutrition.
Finding a Basic Food Allergy Test
How to get tested
Food sensitivity testing is normally conducted in a doctor’s office, clinic, or medical laboratory. The procedure depends on the specific test being used. Tests are prescribed by a doctor after reviewing your symptoms to determine the most probable sensitivity or intolerance.
Can I take the test at home?
At-home testing is available for certain types of food sensitivities. Some tests for lactose intolerance and celiac disease can be done with at-home kits to obtain a blood sample that is then sent by mail to a laboratory.
It’s important to note that while some at-home tests for IgE, lactose intolerance, or celiac disease exist, home IgG food sensitivity tests may not accurately diagnose sensitivities or intolerances. A positive result on at-home testing usually requires follow-up tests prescribed by a doctor.
How much does the test cost?
The cost of testing for food allergies or sensitivities depends on the type of test that is performed, where the test is conducted, and whether you have medical insurance. Testing is often covered by insurance when ordered by a doctor, although you may still be responsible for costs such as copays and deductibles.
Taking a Basic Food Allergy Test
Food allergy testing is typically a straightforward process that begins with a review of your symptoms and medical history. Based on this information, a healthcare provider selects the most appropriate test, such as a blood test or skin test, to evaluate possible immune reactions to specific foods.
Before the test
Before taking a test for food sensitivities, your clinician will review your symptoms and medical history to determine the most appropriate testing strategy. You may be asked to stop certain medications (like antihistamines) before testing, or may have to fast for a period of time for certain types of bloodwork.
During the test
Depending on the type of test, blood may be drawn, or a skin prick test performed. Skin tests involve placing a tiny amount of allergen under the skin to observe reactions.
After the test
If blood is drawn, slight soreness or bruising can occur but typically isn’t long-lasting. You can return to normal activities after a blood draw.
As for results, they should be interpreted in context. A positive IgE allergy test may indicate sensitization, but symptoms and medical history are essential to confirm a true allergy. Allergies or intolerances may require follow-up tests or elimination diets. Treatment plans are made based on symptoms and test outcomes.