What Are Food Allergy Tests

In a food allergy, the immune system responds to a food that is normally harmless as if it were a dangerous infectious agent, a virus, bacteria. The immune system’s response to a food allergy varies from a mild rash or abdominal pain to life-threatening complication called anaphylactic shock.

Food allergies are mainly found in children than in adults. Many children overcome their allergies over time. Almost 90 per cent of these allergies is caused by:

  • Milk
  • Soy
  • Wheat
  • Eggs
  • Tree nuts (for example, almonds, walnuts, pecans and cashews)
  • Fish
  • Seafood
  • Peanuts

What Happens During Food Allergy Tests

Oral Tolerance Test: The allergist gives you or your child small amounts of the food that is suspected of causing the allergy. The food can be provided in a capsule or by injection. The allergist will watch you carefully to see if you have an allergic reaction. If so, it will offer treatment immediately.

Skin Prick: The allergist or health professional places some of the suspicious food on the skin of the forearm. Then gently open the skin with a needle to allow a very small food to enter. If an itchy red bump forms at the puncture site, then he is allergic to the food.

Blood Tests: This test detects substances called IgE antibodies in the blood. The body system produces IgE antibodies when a person is exposed to a substance that causes an allergic reaction. During the Latent food allergen testing [ตรวจภูมิแพ้อาหารแฝง which is the term in Thai], the healthcare professional takes a sample from a vein in an arm with a needle. After inserting the needle, draw some blood and place it in a test tube. You may feel discomfort when the needle enters or removed, but the procedure usually takes few minutes.