What is bruising after tb test?

A tuberculosis (TB) skin test involves injecting a small amount of purified protein derivative (PPD) under the skin. After 48-72 hours, a healthcare provider reads the test and looks for signs of a reaction, including swelling and redness. Some people may experience bruising at the site of the injection. This is usually a mild side effect and should go away on its own within a few days. If there is excessive bruising or pain, it is recommended to contact a healthcare provider. It is also important to note that a positive TB test does not necessarily mean that a person has active TB disease but may indicate exposure to the bacteria. Further testing is needed to determine if treatment is required.