Tuberculin skin test (TST)

The Tuberculin skin test (TST), also known as the Mantoux test, is a method to check if someone has been exposed to the bacteria that cause tuberculosis (TB). A small amount of a protein derived from the bacteria is injected just under the skin of the forearm. After 48 to 72 hours, a healthcare provider examines the injection site to see if there’s a raised bump. The size of the bump helps determine if the test result is positive, suggesting possible TB exposure, or negative, showing no evidence of infection. It’s an important tool for TB screening.