During PPD injection, what should be observed at the injection site?

During PPD injection, what should be observed at the injection site?

• A. A bruise at the injection site
• B. A wheal at the injection site
• C. Bleeding from the injection site
• D. No reaction

Answer: (B)

The key idea is that an intradermal PPD (tuberculin) skin test should produce a small raised bump, or wheal, at the injection site. This wheal shows the needle delivered the tuberculin into the superficial layers of the skin (the dermis) as intended. If you see a wheal, it confirms proper technique for the injection itself. A bruise or bleeding would suggest trauma or improper placement, and no reaction would indicate the injection may not have been delivered correctly. Remember, the wheal is the immediate sign of correct intradermal administration, while the test result is read later by measuring induration (not the wheal) after 48–72 hours.

The key idea is that an intradermal PPD (tuberculin) skin test should produce a small raised bump, or wheal, at the injection site. This wheal shows the needle delivered the tuberculin into the superficial layers of the skin (the dermis) as intended. If you see a wheal, it confirms proper technique for the injection itself. A bruise or bleeding would suggest trauma or improper placement, and no reaction would indicate the injection may not have been delivered correctly. Remember, the wheal is the immediate sign of correct intradermal administration, while the test result is read later by measuring induration (not the wheal) after 48–72 hours.