Intradermal Allergy Testing on Patient in Clinic - AllerVie Health

What is an Intradermal Allergy Test?

An intradermal allergy test involves injecting a small amount of allergen under the skin. This is typically done after a scratch test if that scratch test has proven inconclusive.

Using a very thin needle, the allergist injects a diluted form of the allergen just below the skin. The section of skin is then closely observed for at least 15 minutes. If the skin reacts to the injection and develops a red, itchy wheal, this indicates that the body has responded to the allergen with an allergy antibody, confirming an allergy. Generally speaking, the larger the reaction in the skin, the higher the patient’s sensitivity to the allergen is.


An intradermal test, your allergist will most likely screen for a variety of allergies. It may take up to 15 minutes to apply all of the allergens to the skin.

Adults usually get the injections in the arm, while children get them in the back. During the operation, you should expect some moderate discomfort. If you have an adverse reaction, you may experience itching and irritation at the site.

Each site must be monitored for at least 15 minutes after the allergen is applied. Your allergist will search for skin reactions while also keeping an eye out for more severe reactions. Overall, intradermal testing takes 30 to 45 minutes and is performed as an outpatient procedure.


  • Both allergy scratch tests and intradermal tests are commonly used in the diagnostic process when diagnosing allergies.
  • An allergy scratch test is usually used as a preliminary test. If the results of a skin test are inconclusive, the allergist will then typically conduct an intradermal test.
  • In either scenario, an allergist may also recommend blood testing if additional information is needed to confirm or refine a diagnosis.