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What is a Skin Test Used For?

Published in Allergy & Infection Diagnosis 2 mins read

Skin tests are used to identify allergic reactions and detect certain infections. They are a valuable diagnostic tool in allergy and immunology.

Identifying Allergies

Skin prick tests, also known as puncture or scratch tests, are commonly used to quickly identify allergies to various substances. These tests can simultaneously check for reactions to up to 50 different substances, including:

  • Pollen: Identifying seasonal allergies like hay fever.
  • Mold: Detecting allergies to molds found in the environment.
  • Pet dander: Pinpointing allergies to animals such as cats and dogs.
  • Dust mites: Diagnosing allergies to microscopic creatures commonly found in house dust.
  • Foods: Determining food allergies that trigger reactions.

The test involves placing a small amount of allergen on the skin and observing the reaction. A raised, red, itchy wheal indicates a positive reaction. This method is considered the "gold standard" for allergy diagnosis when used in conjunction with a patient's medical history.

Detecting Infections

Beyond allergies, skin tests are employed to diagnose infections. A notable example is the Tuberculin Skin Test (TST), also known as the Mantoux test, which is used to determine if a person has been infected with Mycobacterium tuberculosis, the bacteria that causes tuberculosis (TB). The test involves an injection of tuberculin (PPD) under the skin. A positive reaction indicates prior exposure to TB bacteria, although further testing may be necessary to confirm active infection.

Other Applications

Research also explores the use of skin tests for detecting other conditions. For example, studies indicate that a skin biopsy might help identify Parkinson's disease and similar disorders with high accuracy.

In summary, skin tests are versatile tools used to diagnose various conditions, primarily allergies and infections, offering a quick and relatively simple way to assess immune responses.