Why is ppd done

At the first visit, the provider will clean an area of your skin, usually the inside of your forearm. You will get a small shot injection that contains PPD. The needle is gently placed under the top layer of skin, causing a bump welt to form. This bump usually goes away in a few hours as the material is absorbed. After 48 to 72 hours, you must return to your provider's office.

Your provider will check the area to see if you have had a strong reaction to the test. Tell your provider if you have ever had a positive PPD skin test. If so, you should not have a repeat PPD test, except under unusual circumstances. Tell your provider if you have a medical condition or if you take certain medicines, such as steroids, which can affect your immune system.

These situations may lead to inaccurate test results. Tell your provider if you have received the BCG vaccine and if so, when you received it.

This vaccine is only given outside of the United States. This test is done to find out if you have ever come in contact with the bacteria that cause TB. TB is an easily spread contagious disease. Minus Related Pages.

Open All Close All. What is it? How is the TST Administered? How is the TST Read? What Are False-Positive Reactions? What Are False-Negative Reactions? The reasons for these false-negative reactions may include, but are not limited to, the following: Anergy Recent TB infection within the past 8 to 10 weeks Very young age younger than 6 months Recent live-virus measles or smallpox vaccination Incorrect method of giving the TST Incorrect measuring or interpretation of TST reaction.

What is a Boosted Reaction? Why is Two-Step Testing Conducted? For persons scheduled to receive a TST, testing should be done as follows: Either on the same day as vaccination with live-virus vaccine or At least 1 month after the administration of the live-virus vaccine. Are there alternative tests to the TST? Diagnosis of TB Disease TB disease is diagnosed by medical history, physical examination, chest x-ray, and other laboratory tests.

What are treatment options for latent TB infection? Additional Information. Guidelines for preventing the transmission of Mycobacterium tuberculosis in health-care settings, MMWR ; 54 No.

Targeted tuberculin testing and treatment of latent tuberculosis infection pdf icon. Section Navigation. Facebook Twitter LinkedIn Syndicate. Testing for TB Infection. Minus Related Pages. Reading the result of a TB skin test. The needle is gently placed under the top layer of skin, causing a bump welt to form. This bump usually goes away in a few hours as the material is absorbed. Your provider will check the area to see if you have had a strong reaction to the test. How to Prepare for the Test.

There is no special preparation for this test. Tell your provider if you have ever had a positive PPD skin test. If so, you should not have a repeat PPD test, except under unusual circumstances. Tell your provider if you have a medical condition or if you take certain medicines, such as steroids, which can affect your immune system. These situations may lead to inaccurate test results.

Tell your provider if you have received the BCG vaccine and if so, when you received it. This vaccine is only given outside of the United States. How the Test will Feel. You will feel a brief sting as the needle is inserted just below the skin surface. Why the Test is Performed. This test is done to find out if you have ever come in contact with the bacteria that cause TB. TB is an easily spread contagious disease.

It most often affects the lungs. The bacteria can remain inactive dormant in the lungs for many years. This situation is called latent TB.