Allergy Skin Test

Allergy Skin Test

An allergy skin test is a noninvasive test used to ascertain allergic reactions to certain allergens. It helps to identify which allergen is causing an allergic reaction in an individual. It is a tool used to diagnose allergies, along with a physical examination and other tests.


To ensure accurate results, the patient should avoid certain activities prior to the allergy skin test. Anything containing epinephrine such as asthma puffers and Primatene Mist should be avoided for four to seven days prior to the test. In addition, antihistamines should be avoided four to seven days prior to the test as they can affect the results. The patient should also notify the doctor if they have used steroid sprays or creams in the weeks prior to the test.

Types of skin tests

The two types of skin tests include a scratch test and a patch test. The scratch test involves dropping a small amount of allergen into a patient’s skin and then scratching or pricking the skin with a needle to allow the allergen to enter. The patch test requires placing a thin patch containing the allergen onto the patient’s back or arm.


The patient is first provided with a questionnaire regarding their medical history and the nature of their allergies. The questionnaire should also include information about current medications. A patch test may also be done first to test for less common allergies such as nickel from jewelry, rubber or fragrances. Next, the patient’s skin is cleaned with an alcohol swab. The allergen is then applied to the skin using either a prick or scratch test. This will introduce the allergen to the skin. The skin is then observed for any reaction on the skin indicating an allergic reaction such as redness, hives, or swelling.


Allergy skin tests are generally safe and have few risks. The most common risks include a reaction to the allergen which can manifest as redness, hives, and swelling. The reaction may be more severe in some cases and can lead to more serious consequences. These risks can be minimized by informing the doctor about other medications and allergies prior to the test.

Why do you need an allergy skin test?

An allergy skin test is necessary to identify the allergen responsible for the allergic reaction. Without the skin test, the allergen may be impossible to identify in some cases. Allergy skin testing is the most accurate and cost-effective way to determine which allergen is causing an allergic reaction.

When should you take an allergy skin test?

An allergy skin test should be taken when there are signs and symptoms suggestive of an allergic reaction. It is important to inform the doctor of any medications that may interfere with the results such as antihistamines or epinephrine in order to get the most accurate results. Additionally, for those taking steroids for chronic conditions, it is important to abstain from taking the steroids prior to the skin test.