Difficulty: Medium
Average Score: 80%
Simulated
The nurse is checking a coworker's tuberculosis (TB) skin test. The forearm has a raised red area about 12 mm in diameter after 72 hours. What is the best interpretation of this skin test?
Correct answer
A
Rationale
A 12 mm induration after 72 hours indicates TB exposure, a positive result. B requires further testing, C is unlikely, and D is incorrect as the reaction is positive.