Skin allergy test

Skin allergy test

A skin allergy test is a medical procedure used to identify allergens responsible for triggering allergic reactions in individuals. This test is commonly performed by allergists or dermatologists to diagnose allergic conditions such as allergic rhinitis, asthma, eczema, and food allergies.

Types of Skin Allergy Tests

There are several types of skin allergy tests, including:

Skin Prick Test

The skin prick test involves placing a small amount of a suspected allergen on the skin, usually on the forearm or back, and then pricking the skin with a needle. If the individual is allergic to the substance, a small raised bump, or wheal, will appear at the test site within 15-20 minutes.

Intradermal Test

The intradermal test involves injecting a small amount of the allergen just under the skin. This test is more sensitive than the skin prick test and is often used when the skin prick test results are negative, but an allergy is still suspected.

Patch Test

The patch test is used to identify contact dermatitis. Small amounts of potential allergens are applied to patches, which are then placed on the skin, usually on the back. The patches are left in place for 48 hours, and the skin is examined for reactions at 48 and 72 hours.

Procedure

Before the test, the patient is usually advised to stop taking antihistamines and other medications that could interfere with the results. During the test, the skin is cleaned with alcohol, and the allergens are applied using the chosen method. The patient is then monitored for any signs of an allergic reaction.

Interpretation of Results

The results of a skin allergy test are interpreted based on the size of the wheal and the presence of redness or swelling at the test site. A positive result indicates an allergy to the tested substance, while a negative result suggests no allergy.

Risks and Considerations

Skin allergy tests are generally safe, but there is a small risk of a severe allergic reaction, known as anaphylaxis. Patients are usually monitored for a short period after the test to ensure their safety.

See Also

• Allergy
• Immunotherapy
• Histamine
• Allergic rhinitis
• Asthma
• Eczema
• Food allergy