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TB Skin Test (Tuberculosis)

What is it?

Tuberculosis Skin Testing (TST), also known as the Mantoux Test or Purified Protein Derivative (PPD), is a screening method for detecting exposure to tuberculosis bacteria(TB). 

How is it done?

A small amount of tuberculosis protein solution is injected under the skin into the forearm. The injection site is then examined between 48 to 72 hours for any reaction, typically a raised bump and sometimes redness at the injection site. The raised bump is your body's reaction to the antigen protein. This is safe and some people have this test done every year.

Who needs it?

Certain occupations and people, particularly those with a higher risk of TB exposure (ie. first responders, working in a hospital or clinic) or employment purposes or school admission requirements.

Frequently Asked Questions (FAQs)

Is the TST painful?

The TST involves a small needle prick, similar to a regular vaccination. Discomfort is minimal.

Can I return to work immediately after a TST?

Yes, there are usually no restrictions on resuming regular activities after the test.

Are there any side effects associated with TST?

Side effects are generally mild and include redness or swelling at the injection site. Severe reactions are rare but should be reported to your healthcare provider

Can medical conditions affect TST results?

Certain medical conditions (ie. cancer, HIV) may influence TST results. It is important to inform your pharmacist about any medical conditions or health conditions before the test.

Is the TST accurate in detecting TB exposure?

While the TST is a valuable tool, no test is 100% accurate. Positive results indicate exposure, but additional testing such as a chest X ray or sputum test may be required for a definitive diagnosis 

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