PPD skin test


PPD Skin Test

PPD stands for Purified Protein Derivative. It is a test done to determine if a person is infected with or has been exposed to tuberculosis (TB). It is a form of a tuberculin skin test, which also helps to diagnose latent tuberculosis infection (LTBI). PPD skin test can sometimes also indicate past or recent TB infection.

Preparation For PPD Skin Test

No specific preparation is needed for a PPD skin test. Do not take aspirin or other pain or fever medications for at least 48 hours prior to the test, as this may interfere with the test result.

Procedure For PPD Skin Test

The procedure for the PPD skin test starts by cleaning the injection site with an alcohol swab. After the site is sterile, the doctor will inject a small amount of the PPD solution (purified protein derivative) just under the skin. This is typically performed on the inside of the lower arm.

Types of PPD Skin Test

  • Tine Test: Uses a small plastic device to prick the skin with several tiny needles. It is easier to do than the intradermal test and will not cause a lot of discomfort.
  • Intradermal Test: Is a needle injected into the skin. This is an older version of the PPD test and is not as commonly used as the tine test because of the discomfort.

Risks of a PPD Skin Test

The PPD skin test is a safe procedure with minimal risk to most people. However, there is a slight risk of infection, bleeding, or swelling at the injection site. In rare cases, there may be an allergic reaction to the PPD solution.

Why Is a PPD Skin Test Done?

The PPD skin test is done to determine if a person has been exposed to tuberculosis. It can sometimes indicate both past and recent exposure. The test is done by injecting a small amount of PPD solution just under the skin. This causes a reaction and the results are usually seen within 48-72 hours.

When to Get a PPD Skin Test?

A PPD skin test is often done in people who are at a higher risk for TB, such as healthcare workers, people who have been exposed to someone with TB, those who have traveled to certain areas, and people with weakened immune systems. It is also commonly done in newborns.