What is PPD TITER?

A PPD titer, or purified protein derivative test, is a skin test used to determine if an individual has been exposed to the bacteria that cause tuberculosis (TB). During the test, a small amount of PPD is injected under the skin, typically on the forearm. After 48 to 72 hours, a healthcare provider checks the injection site for any swelling or redness, which indicates a reaction. A positive result suggests TB exposure, but further testing is needed to confirm an active infection.