TB Skin Test

Service Description

A Tuberculosis (TB) skin test, also known as the Mantoux test or PPD test, is a diagnostic procedure used to determine if a person has been exposed to the bacterium Mycobacterium tuberculosis, which causes tuberculosis. This is usually requested by specific occupational employers. Test Administration: The TB skin test is performed by a healthcare professional, usually a nurse or medical assistant. It involves injecting a small amount of purified protein derivative (PPD), a substance derived from the tuberculosis bacterium, just under the top layer of the skin on the forearm. Injection Site: The injection is typically made on the inner part of the forearm, near the elbow. The healthcare provider uses a very fine needle to introduce the PPD solution just beneath the surface of the skin, creating a small, raised bump. Waiting Period: After the injection, the patient must wait for 48 to 72 hours before the test is read. During this time, it's essential to keep the injection site dry and avoid scratching or rubbing the area. Test Reading: When the specified waiting period has passed, the healthcare provider examines the injection site. They measure the size of any swelling or redness at the injection site. A positive reaction typically results in a raised, red bump at the site. It's important to note that a positive TB skin test does not necessarily mean a person has active tuberculosis. It signifies exposure to the bacterium or a latent infection. The test helps identify individuals who may need further evaluation and medical attention to prevent the development of active TB disease.