If you are showing signs of having a food allergy, or even seasonal allergies, your physician will likely recommend you to an allergist to perform testing. These tests are designed to help diagnose an allergy, so you can receive further treatment. Methods of testing include: skin test, blood test, or an oral food challenge.
WHAT IS A SKIN TEST?
- A small, liquid portion of the allergen is placed on the skin. Then, the skin is gently pricked to allow the allergen to superficially enter the skin. After 15 to 20 minutes if a raised red bump appears, then the test is positive: confirmed allergy.
- Usually performed on your back or arms. Don’t worry, the bumps do not last for long!
- Process is relatively painless and results are quick.
- This is commonly used for testing allergies to items such as dust, mold, pollen, and animal hair.
WHAT IS A BLOOD TEST?
- A small amount of blood is drawn from a vein in the arm to perform tests that measure the allergy-related antibody immunoglobulin E (IgE) in the bloodstream after an allergen is introduced.
- In the blood test, allergists are testing individual proteins for a reaction, which means you can find out exactly which proteins you are allergic to in each allergen. For more about this process, read this post from Thermofisher.
- Results are slow, can take a up to a week or longer.
- This method is recommended for individuals who have serious skin conditions or a history of severe allergic reactions such as anaphylaxis. There is no risk of severe allergic reaction for a blood test.
- It is one of the more expensive methods and may not be covered by insurance.
WHAT IS AN ORAL FOOD CHALLENGE?
- Under medical supervision, a very small portion of an allergen is fed to the patient at an allergist’s office or food challenge center to see if a reaction occurs. If a reaction occurs, then food allergy diagnosis is confirmed.
- In case of a severe reaction there is emergency medication, equipment, and personnel on hand.
- Process can be scary and intimidating, but results are instantaneous.
- This is also a common process for when a child tests to see if they have outgrown a food allergy.