Tuberculin Skin Test (TST)
Procedure (Note -This synopsis is intended to provide a basic understanding of the TST procedure; to provide greater detail is beyond the scope of this course.)
1. The standard TST is performed using the Mantoux technique, where a 0.1 mL of 5 tuberculin units of tuberculin purified protein derivative (PPD) is injected intradermally (into the top layers of skin) on the forearm (also known as the volar surface), using a 27 gauge needle and a tuberculin syringe.
2. Trained providers read the skin test after 48-72 hours.
3. The presence or absence, and the diameter of induration (hard bump) is measured in millimeters.
7. CDC. Administering the TST. Slide #23 from Targeted Tuberculosis (TB) Testing and Treatment of Latent TB Infection – Download complete slide set - the slide set is in the public domain. Centers for Disease Control and Prevention site. September 2016. Accessed March 17, 2022. https://www.cdc.gov/tb/publications/slidesets/ltbi/default.htm 8. CDC. Reading the TST. Slide #24 from Targeted Tuberculosis (TB) Testing and Treatment of Latent TB Infection – Download complete slide set- the slide set is in the public domain. Centers for Disease Control and Prevention site. September 2016. Accessed March 17, 2022. https://www.cdc.gov/tb/publications/slidesets/ltbi/default.htm
