An allergy test is an exam performed by a trained allergy specialist to determine if your body has an allergic reaction to a known substance. The exam can be in the form of a blood test, a skin test, or an elimination diet.
The skin is exposed to different types and numbers of allergens (allergy-causing substances) to see if an allergic reaction occurs. As the allergens are in liquid form they can be put on or just under the skin.
Allergies occur when your immune system, which is your body’s natural defense, overreacts to something in your environment. For example, pollen, which is normally harmless, can cause your body to overreact. This overreaction can lead to:
- a runny nose
- blocked sinuses
- itchy, watery eyes
Types of allergens
Allergens are substances that can cause an allergic reaction. There are three primary types of allergens:
- Inhaled allergens affect the body when they come in contact with the lungs or membranes of the nostrils or throat. Pollen is the most common inhaled allergen.
- Ingested allergens are present in certain foods, such as peanuts, soy, and seafood.
- Contact allergens must come in contact with your skin to produce a reaction. An example of a reaction from a contact allergen is the rash and itching caused by poison ivy.