Which route should the nurse use to administer the purified protein derivative (PPD)?

To administer the purified protein derivative (PPD), the correct method is intradermal. This approach is specifically designed to create a localized immune response that allows for accurate assessment of exposure to tuberculosis (TB) antigens. By injecting the PPD just beneath the surface of the skin, a small, controlled amount of the substance can be observed for a reaction, typically within 48 to 72 hours.

The intradermal route is important because it ensures that the PPD is delivered to the intradermal layer, which is rich in immune cells. This optimal placement facilitates the appropriate immune response necessary for the test to be valid. The size of the induration (swelling) that develops at the injection site is what is measured to evaluate the test results.

Other routes, such as subcutaneous, intramuscular, or oral, do not provide the same localized reaction or accurate results required for the PPD test. Subcutaneous injections penetrate deeper into the tissue, often dispersing the substance too broadly, while intramuscular injections deliver medication into a muscle, which is not suitable for this specific test. Oral administration is not appropriate for PPD, as it needs to be presented directly to the immune system through the skin to el