What is the time frame for results from a tuberculin skin test?

The appropriate time frame for reading the results of a tuberculin skin test is 48 to 72 hours after the application of the test. This is because the test measures a delayed hypersensitivity reaction to the Mycobacterium tuberculosis antigens. If the test is read too soon, there may not be enough time for the immune response to manifest as a palpable induration, leading to the possibility of inaccurate interpretation. Therefore, a time frame of 2 to 3 days allows for optimal observation of any reaction that indicates a person's sensitization to tuberculosis antigens.