How soon after a Mantoux test should it be read?

The Mantoux test, also known as the tuberculin skin test, is used to determine if a person has been exposed to the tuberculosis (TB) bacteria. The reaction to the test is measured by a healthcare professional to assess whether it is positive or negative. It is crucial that the test is read within the correct timeframe to ensure accurate results.

The optimal time frame to read the Mantoux test reaction is between 48 to 72 hours after administration. This period allows enough time for an immune response to develop if the person has been exposed to TB. Reading the test too early may result in a false negative, as the body hasn’t had sufficient time to react to the antigen injected under the skin. Conversely, reading it after 72 hours may complicate the evaluation due to the potential for reaction fading or other skin changes unrelated to the test.

Therefore, reading the Mantoux test between 48 to 72 hours post-administration is essential for reliable interpretation of the results, making this choice the correct one.