Wheat allergy tests

If you suspect that you have a wheat intolerance or wheat allergy the first step is to discuss it with your doctor. Wheat is one of the eight most common allergy-causing foods so your doctor should take you seriously and evaluate your case. They should ask you detailed questions about your symptoms and will also ask you to keep a detailed food diary listing any symptoms or reactions against the foods eaten. You doctor may also ask you to eliminate wheat from your diet for a set period of time, then re-introduce it and see what reactions occur.

If your doctor suspects that you do have a wheat allergy or intolerance they will refer you for a skin prick test, this is usually the first test undertaken in suspected allergies because it's simple to do and the results will be returned in a relatively short amount of time, usually 15-30 minutes.

Wheat allergy tests:

Skin Prick Test

In this test your skin will be exposed to small amounts of various allergens. The test measures specific IgE (immunoglobulin E) attached to cells in the skin in allergies called "mast" cells.

You will be asked to avoid taking any anti-histamines or other specific drugs for a period of time before the tests are carried out, from days to weeks depending on the drug.

This test should not cause a violent reaction to the suspected allergen, and almost anybody can be tested, however where there has been a clear anaphylactic reaction to ingestion of a specific allergen then skin testing may not be appropriate. The skin of elderly people may also be incapable of reacting in some cases.

  • A grid or codes will be marked along the underside of your forearm, possibly both arms.
  • Small drops of each allergen will be placed in the centre of each grid square or by each code, as few as 6 or as many as 70 can be done in one session.
  • A lancet will be used to scratch in the centre of the allergen droplet (tiny little scratch which shouldn't be painful).
  • The allergen drops will also include 1-2 'control' drops (saline [negative control] and a histamine [positive control]). The saline is used to check that you don't have hyper-sensitive skin and react to the lancet breaking the skin rather than the allergen itself. The histamine is used because everyone is expected to react to it.
  • The allergens may be drawn from several groups e.g. foods, household, animals etc.
  • If you are allergic to the allergen drop placed on your skin then a hive (red, itchy raised bump) will form under the particular allergen drop you are reacting to.
  • It may be itchy, but it's important not to scratch any of the test sites.
  • At the end of the waiting period the test sites will be inspected for hives, the allergen it relates to will be noted and the size of the hive measured. After approximately an hour any hives will usually begin to disappear.
  • It is important to note that false negative reactions can occur in some instances, and food allergens are less reliable than other allergen types. However an allergy specialist is the best person to carry out and interpret these tests.

Your doctor may also recommend that you undergo a blood test.

Blood Test

A blood test can measure your immune system's response to wheat by measuring the amount of immunoglobulin E (IgE) antibodies in your bloodstream.

Blood testing can be particularly useful if the skin prick tests can't be carried out, for example if an anaphylactic reaction may occur, the person has skin problems such as eczema or psoriasis, or the person was unable to stop their medication e.g. anti-histamines.

  • A small sample of blood is taken.
  • The blood sample is analysed by subjecting it to tests for wheat sensitivity.
  • Results take approximately 7-14 days and will indicate the class of wheat sensitivity.
  • Classes of sensitivity range from 0-6, where class 0 = negative, class 1 = minor sensitivity up to class 6 = extremely high sensitivity.

Your doctor may also wish to rule out other medical problems that may be the cause of the symptoms. For example they may want to test for coeliac disease/gluten intolerance, especially if there are reactions to other grains.

The two tests listed above, skin prick and blood, are two tests that a medical professional will want you to undergo if wheat allergy or intolerance is suspected. There are however a number of other tests that are advertised, and some of these tests can be quite expensive. These tests are often unreliable, can leave you with a false positive list of all the foods you can't eat, and many aren't carried out by anyone with medical background or specialist allergy training. These tests should be treated with caution.

This page is not to be taken as medical advice:

No information on this page or website should be taken as medical advice. You SHOULD ALWAYS consult your General Practitioner and/or Paediatrician together with a registered Dietician in all instances of suspected food allergy or intolerance.