What are typical steps for performing a tuberculin skin test injection?

What are typical steps for performing a tuberculin skin test injection?

• A. 45-degree angle; 18 gauge needle; inject 1 mL subcutaneously; massage.
• B. 10–15 degree angle, 25–27 gauge needle, inject 0.01 mL to 0.1 mL intradermally to create a wheal; do not massage.
• C. 90-degree angle; 25 gauge; inject 2 mL intramuscular.
• D. 5-degree angle; 30 gauge; inject 0.5 mL intradermally.

Answer: (B)

The key is delivering a very small amount of tuberculin into the dermis to form a visible wheal, which confirms the skin will respond if exposed to TB. This requires an intradermal, rather than subcutaneous or intramuscular, technique using a fine needle and a tiny volume. Use a narrow gauge needle (25–27) and insert the needle just under the skin at a shallow angle (about 5–15 degrees) with the bevel up. Inject a small volume, about 0.01 to 0.1 mL, to create a wheal roughly 6–10 mm in diameter. Do not massage the area after the injection, as rubbing can break the wheal and affect the test result. The other methods would place the substance too deep (subcutaneous or intramuscular), use an inappropriate angle, or deliver too large a volume, all of which would fail to produce the proper wheal and yield unreliable results.

The key is delivering a very small amount of tuberculin into the dermis to form a visible wheal, which confirms the skin will respond if exposed to TB. This requires an intradermal, rather than subcutaneous or intramuscular, technique using a fine needle and a tiny volume.

Use a narrow gauge needle (25–27) and insert the needle just under the skin at a shallow angle (about 5–15 degrees) with the bevel up. Inject a small volume, about 0.01 to 0.1 mL, to create a wheal roughly 6–10 mm in diameter. Do not massage the area after the injection, as rubbing can break the wheal and affect the test result.

The other methods would place the substance too deep (subcutaneous or intramuscular), use an inappropriate angle, or deliver too large a volume, all of which would fail to produce the proper wheal and yield unreliable results.