Tuberculin tine test Health Article

Definition

The tuberculin tine test is used to determine whether someone has been infected with the bacteria that causes tuberculosis. However, the test is rarely used because other tests are more accurate.

Alternative Names

TB tine

How the test is performed

This test uses a tiny spiked instrument to inject a small amount of the tuberculosis antigen just under your skin. This is most commonly done on the forearm. Usually, the area is marked with an ink pen so it can be checked for any redness and swelling at a later time, usually in 2 - 3 days.

Note: Another test, called the tuberculin skin test, is more accurate than the TB tine test covered in this article. It is the preferred method of determining exposure to tuberculosis.

How to prepare for the test

There is no special preparation. People with dermatitis or other skin irritations on their arms may need to have the test performed at a different spot on the body.

How the test will feel

Some people feel a slight stinging sensation when the instrument is inserted under the skin. After the test, the area may itch or burn.

Why the test is performed

This test helps determine if you have ever been exposed to, or infected with tuberculosis. If you have ever been infected with tuberculosis, your immune system produced substances called T-cells to help fight the disease. These T-cells stay in your body.

When this test is performed, the T-cells against tuberculosis will produce a positive test result.

Normal Values

If you have a negative test result, the area may be a little red, but it will not be swollen and firm like a mosquito bite. This means you have not been infected with the bacteria that cause tuberculosis.