Final answer:
The nurse should insert the needle at a 15° angle when administering a tuberculin skin test. This test screens for potential tuberculosis (TB) exposure and involves injecting tuberculin protein derivative into the skin to elicit a delayed hypersensitivity reaction.
Step-by-step explanation:
When administering a tuberculin skin test, the nurse should insert the needle at a 15° angle.
The tuberculin skin test, also known as the Mantoux test, is used to screen for potential tuberculosis (TB) exposure. The test involves injecting tuberculin protein derivative into the skin and examining the area for a delayed hypersensitivity reaction. The needle should be inserted at a 15° angle to properly inject the tuberculin into the skin.
A positive result is indicated by redness, swelling, or hardness at the injection site, which signifies a cellular immune response to TB antigens.