PPD - PT2 Read
TB skin test/TST-skin
- 15 min15 minutes
- Main Office
Understanding your PPD skin test results. If the area of skin where you received the PPD injection isn't swollen or is only slightly swollen 48 to 72 hours after the injection, the test results are negative. A negative result means that you most likely haven't been infected with the bacteria that cause TB. False-positive and false-negative results People who received a bacillus Calmette-Guérin (BCG) vaccine against TB may have a false-positive reaction to the PPD test. Some countries outside the United States that have a high prevalence of TB give the BCG vaccine. Many people born outside of the United States have had the BCG vaccine, but it’s not given in the United States due to its questionable effectiveness. Your doctor will follow up on positive results with a chest X-ray, a CT scan, and a sputum test that looks for active TB in the lungs. The PPD skin test isn’t foolproof. Some people infected with the bacteria that cause TB may not have any reaction to the test. Diseases such as cancer and medications like steroids and chemotherapy that weaken your immune system may also cause a false-negative result.
8502 Brookville Road, Indianapolis, IN, USA