What does a negative TB test look like?

What if my TB skin test is negative? The test is “negative” if there is no bump (or only a very small bump) at the spot where the fluid was injected. A negative TB skin test usually means that you don’t have TB. In some situations, you may need to have another TB skin test later.

What is a negative TB skin test reading?

Understanding your PPD skin test results. If the area of skin where you received the PPD injection isn’t swollen or is only slightly swollen 48 to 72 hours after the injection, the test results are negative. A negative result means that you most likely haven’t been infected with the bacteria that cause TB.

Can you have TB and test negative?

– Negative skin test: This means the person’s body did not react to the test, and that LTBI or TB disease is not likely. If your exposure to TB germs was recent, your TB skin test reaction may not be positive yet.

Does a negative TB test turn red?

Redness alone at the skin test site usually means you have not been infected with TB bacteria. A firm red bump may mean you have been infected with TB bacteria at some time. The size of the firm bump (not the red area) is measured 2 to 3 days after the test to determine the result.

As the provider examines your arm, then they can determine whether you have TB or not. In a negative response, the skin will most likely not be bright reddish, hard or look influenced. It will look like the day you received the injection , but there might be a little redness or indentation.

How do you take a TB test?

The TB skin test (Mantoux tuberculin skin test) is performed by injecting a small amount of fluid (called tuberculin) into the skin in the lower part of the arm. A person given the tuberculin skin test must return within 48 to 72 hours to have a trained health care worker look for a reaction on the arm.

What are the signs of a positive TB skin test?

A person with TB disease has a positive TB skin test, an abnormal chest x-ray (usually) and symptoms of TB disease (coughing for more than 3 weeks, fever, night sweats, fatigue, unexplained weight loss, loss of appetite, and/or others).

What are the different types of TB testing?

There are two types of TB (tuberculosis) tests. One is a TB skin test (also known as a PPD test) and the other is a TB blood test (QuantiFERON®-TB Gold).