Your questions answered about tuberculin skin testing.

1. To understand TB skin testing, it is necessary to have a basic understanding of the disease process and the role of the immune system. 2. The Mantoux test is the tuberculin skin test of choice, the intermediate strength (5 TU) being the most commonly used. 3. Either the palpation method or the ball-point pen technique may be used to measure induration that results from TB skin testing. An induration of 10 mm or greater is considered significant. 4. TB skin testing should be administered regardless of patient history of BCG vaccination. To eliminate the confusion caused by the booster phenomenon, a two-step procedure is recommended for individuals who at initial screening have an induration of 5 to 9 mm.