Which of the following best describes the Mantoux test?

The Mantoux test, also known as the tuberculin skin test, is a specific diagnostic tool used to determine if a person has been exposed to the bacteria that causes tuberculosis (TB). This test involves the intradermal injection of a purified protein derivative (PPD) of the tuberculin, which is a substance derived from the TB bacterium. After the injection, the healthcare provider examines the area for a reaction, typically a raised area of swelling, after 48 to 72 hours. A positive reaction indicates that the individual has been exposed to TB and may either have an active infection or a latent infection requiring further evaluation.

This method is distinct from other testing modalities like blood tests, breath tests, or urine tests, which do not utilize the intradermal injection method and are not classified as skin tests. Blood tests for tuberculosis, such as the interferon-gamma release assays (IGRAs), evaluate immune response to specific TB proteins, while both breath and urine tests are not standard methods for diagnosing TB. The Mantoux test remains a valuable screening tool in many settings, particularly in populations at risk for TB.