The TB test is called a tuberculin skin test (TST).
Understanding the Tuberculin Skin Test
The tuberculin skin test is a common method used to detect a tuberculosis (TB) infection. It's important to note that the test indicates if you have been infected with the Mycobacterium tuberculosis bacteria, not if you have active TB disease.
Different Names for the Same Test
While the technical term is tuberculin skin test (TST), you might hear it referred to by other names. These terms are often used interchangeably:
- Mantoux test: This refers to the specific technique used to administer the TST by injecting a small amount of purified protein derivative (PPD) under the skin.
- TB skin test: A simple, general term used to describe the test.
- PPD test: Another term that references the purified protein derivative used in the test.
How the TST Works
The test involves injecting a small amount of fluid called tuberculin or purified protein derivative (PPD) under the skin, usually on the forearm. After 48 to 72 hours, a healthcare professional will examine the injection site for any reaction, such as swelling or redness.
Interpretation of Results
The results of the test are based on the size of the raised area, not the redness, which is measured in millimeters. A positive result suggests that a person has been infected with TB, but further tests are needed to determine whether the infection is latent (inactive) or active.
Key Takeaways
- The TB test is officially known as a tuberculin skin test (TST).
- Other common names include Mantoux, TB skin test, and PPD test.
- The Mantoux refers to the specific technique of administration of the test.
- The test detects exposure to the TB bacteria, not active TB disease.
