Your patient had a TB skin test done on Thursday at 2:45 PM. When should the test be read?

The TB skin test, also known as the Mantoux test, typically needs to be read 48 to 72 hours after the administration of the test. Given that the test was administered on Thursday at 2:45 PM, the earliest time to read the test would be 48 hours later, which falls on Saturday at the same time.

Since Saturday at 3 PM is an hour after the 48-hour mark, it still falls within the appropriate reading window of 48 to 72 hours. Conversely, reading the test sooner than 48 hours, such as on Friday or earlier Saturday, would not provide an accurate assessment of the body's immune response to the tuberculin. Thus, in the context of the timing required for an accurate reading of the TB skin test, Saturday at 3 PM is the best choice.