In a tuberculin test, the tuberculin antigen is injected into the skin of your forearm.

If you have been exposed to tuberculosis (TB), an infectious disease caused by a microorganism called mycobacterium tuberculosis, the body's immune response will cause an inflammatory reaction at the injection site. However, the tuberculin test cannot distinguish between active and dormant tuberculosis infection.

Purpose of the Tuberculin Test
The TB test screens a person for exposure to tuberculosis. This test may be performed yearly in people with a weakened immune system. It also detects a previous infection with the bacterium M. tuberculosis and determines the need for further testing to distinguish tuberculosis from other illnesses that affect the lungs.

Who can perform a tuberculin test?
A paramedic, nurse, or doctor.