Tests and diagnosis

By Mayo Clinic Staff

Your doctor will likely use a combination of tests, including a physical exam, to make a diagnosis. Tests or diagnostic tools may include:

  • Skin test. In this test, tiny drops of purified allergen extracts — including extracts for wheat proteins — are pricked onto your skin's surface. This is usually carried out on the forearm, but it may be done on the upper back. The drops are left on your skin for 15 minutes before your doctor or nurse observes your skin for signs of allergic reactions. If you're allergic to wheat, you'll develop a red, itchy bump where the wheat protein extract was pricked onto your skin. The most common side effect of these skin tests is itching and redness.
  • Blood test. In some cases a skin test can't be performed because of the presence of a skin condition or because of interactions with certain medications. As an alternative, your doctor may order a blood test that screens for specific allergy-causing antibodies to various common allergens, including wheat proteins.
  • Food diary. A detailed record of what and when you eat, as well as when you experience symptoms, may help your doctor identify the cause of a food allergy.
  • Elimination diet. Your doctor may recommend a diet with certain foods removed, particularly those foods that are common allergens. Under your doctor's direction, you will gradually add foods back into your diet and note when symptoms return.
  • Food challenge testing. With this test, you eat capsules containing the food suspected of being the allergy-causing agent. Under careful supervision for a few hours or days, usually at a hospital, you begin with a small amount of the food and gradually increase the amount you consume. During the test, you're monitored for any allergy symptoms.
Jul. 07, 2011