TB Skin Testing

TB Skin Test (TST)

TB skin testing is a screening method used to identify those who have been exposed to the Tuberculosis infection. TST does not diagnose TB as a disease. TST is not a vaccine for Tuberculosis. It is a purified derivative solution that is injected under the first layer of skin, usually on the forearm.

When your TST is administered, you will be asked to return in 48-72 hours to have it read. This is the amount of time to read your TST for an accurate result. If we are not able to read the skin test within 48-72 hours, you may have to repeat your skin test.

Two step TB testing is common for those in health care and other professions. This requires two skin tests being placed within a certain amount of time. Your second TB skin test can be placed anytime between 7-21 days after your first skin test was placed. This is the required amount of time. Both skin tests must be read and documented to qualify as a 2-step TB Skin Test.

If you are a Positive Reactor and have proper documentation (MD report, documentation for completion of treatment, previous Positive Reactor form/card) then you can make an appointment at the TB clinic for an Annual Positive Reactor Form. We do not do chest x-rays for annual evaluations. If you do not have proper documentation, then you will have to undergo evaluation which may include a TB skin test or further diagnostic testing. You can also call our TB clinic to make an appointment at (309) 888-5435. Please state you are a Positive Reactor when you call to make your appointment.

For more information on TB skin testing, read this TB skin testing information sheet (PDF).