A TB skin test is administered to individuals who are at a higher risk of being exposed to tuberculosis. The test involves injecting tuberculosis antigen under the skin using a spiked instrument, which can cause skin irritation and itching.
An individual can be allergic to a preservative in the tuberculosis antigen used in the test. In which case, any itching or irritation would not be associated with the results of the TB test.
Mild itching and irritation is not abnormal and does not necessarily signify an individual is positive for TB. A test is considered positive only if a bump greater than 100mm forms, and then an x-ray is administered for confirmation.
For mild itching, a cold washcloth can be applied to the area to alleviate some of the discomfort. Putting a bandage over the area can help prevent unconscious itching.
Individuals receiving a TB test should be conscious of not rubbing or scratching the skin where the test was administered. This can further irritation and can open the wound, creating a greater risk of infection.
If severe itching was experienced in previous TB tests, an individual can request a chest X-ray instead of the skin test.