What is tuberculin, purified protein derivative (PPD)?

Tuberculin, purified protein derivative (PPD) is a substance that's used to detect exposure to tuberculosis (TB). Tuberculin helps detect this infection by causing a mild reaction in people who have been infected with TB. Tuberculin is given as an injection by a healthcare professional at a hospital, clinic or doctor's office. This liquid will be injected under the skin, usually on the forearm. The results will be apparent within 48 to 72 hours. If you develop a hardened bump on your skin at the injection site, you may have tuberculosis. Even if you do not develop a reaction, it is important to go to your follow-up appointment to have your results evaluated by a professional because you may need a second test. Usually, TB testing is recommended for people who have been exposed to tuberculosis or who are at high risk for tuberculosis. These people include: those with HIV, those who are from, or have visited, a country where tuberculosis is common (the Caribbean, Latin America, Africa, Asia and Russia), those who live in a place in the United States where tuberculosis may be passed easily (prison, some nursing homes, homeless shelters) and those who inject illegal drugs. Various brands of tuberculin PPD are available, including Tubersol and Aplisol. Talk to your doctor to determine whether tuberculosis testing with tuberculin PPD is appropriate for you.