What is it?

Tuberculosis (TB) is a bacterial infection that can damage the lungs or other parts of the body. The TB skin test can tell if your child has TB bacteria in their body. Many people are exposed to TB and test positive for TB bacteria in their bodies, but they don't get the disease. TB bacteria can stay in your child's body without making your child sick. This is because your child's immune system can keep TB in check.

Why is the test done?

Your doctor may want your child to have a tuberculin skin test if:

• Your child has been in close contact with someone who has tuberculosis (TB).
• Your child has symptoms that might be causing TB. Symptoms may include a cough that doesn't go away, a fever, or weight loss.

How do you prepare for the test?

In general, there's nothing you have to do before this test, unless your doctor tells you to.

How is the test done?

During the skin test, part of a tuberculosis bacterium is injected under your child's skin. The test will feel like a skin prick.

What happens after the test?

• Do not cover the site with a bandage.
• Your child must see the doctor again 2 to 3 days after the test to have the skin test checked. If your child has TB in their body, a firm red bump will form at the shot site within 2 days.
• If the test shows that your child is infected with TB (positive), the doctor probably will order more tests. A TB-positive skin test can't tell when your child became infected with TB. And it can't tell whether the infection can be passed to others.

How can you care for your child at home?

• Do not let your child scratch the test site. Scratching it may cause redness or swelling. This could affect the test results.
• To ease itching, put a cold face cloth on the site. Then pat the site dry.
• Do not cover the test site with a bandage or other dressing.