mcavoy111 - 22 April 2009 11:12 PM
How long does it take to find out if you have tuberculosis?
The Mantoux PPD tuberculin skin test is stated to be the most reliable. The test is usually given on the inside of the forearm about halfway between the wrist and the elbow, where a small bubble will form as the tuberculin is injected. The skin test takes just a minute to administer.
After 48-72 hours, the test site should be examined by a trained person for evidence of swelling. People who have been exposed to tuberculosis will develop an immune response, causing a slight swelling at the injection site. If there is a lump or swelling, the health care provider will use a ruler to measure the size of the reaction. Some public health physicians recommend using a 72-hour waiting period as a general practice on the grounds that a 48-hour waiting period yields a higher percentage of false negative test results.