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‚ÄčTuberculosis (TB) Skin Test

Why Do I Need a TB Skin Test?

Tuberculosis (TB) is a contagious disease that is spread by coughing. A TB skin test will show whether someone has been exposed to TB germs and may be done for the following reasons:

  • You have been in contact with a person who has infectious TB disease
  • It is a requirement for employment
  • To determine past exposure as part of a medical assessment

What Is A TB Skin Test?

  • A small amount of fluid is injected under the skin of your arm. This is not a vaccination
  • After 2-3 days, a nurse or doctor will look at your arm
  • If a bump is present, it is measured with a ruler. Only bumps that are a large size are considered significant
  • If the skin test is positive, you will be asked to see your doctor. A chest x-ray will be done to see if TB disease is present.

What Reaction Can I Expect At The Test Site?

There may be swelling or redness at the injection site, and slight discomfort such as itching.

Does A Positive Skin Test Mean That I Have Tuberculosis?

A positive skin test means that you have been exposed to the TB germ at some time in your life. You have Inactive TB, or Latent TB. It does not mean you have tuberculosis disease. You will be referred to your family doctor for assessment. A chest x-ray is needed to determine if the TB germs have done any damage to your lungs. Your doctor may prescribe medication to prevent TB.

Additional Information

  • The TB skin test cannot give you Tuberculosis
  • You can still get the skin test even if you are pregnant or have history of previous pregnancy.
  • Keep a record of your TB skin test. A positive skin test is not usually repeated, as the test will continue to react positive.