The process for giving a PPD (Purified Protein Derivative) skin test, also known as a Mantoux test, involves several key steps to ensure accurate results. Based on the provided reference, here’s how it's done:
Step-by-Step Guide to Administering a PPD Skin Test
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Prepare the Site:
- Location: Identify the correct injection site on the forearm. This should be approximately 5–10 cm (2–4 inches) below the elbow joint.
- Positioning: Place the forearm palm-up on a firm and well-lit surface for easy access and visibility.
- Cleaning: Thoroughly clean the injection site using an antiseptic.
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Prepare the Syringe:
- Check Expiration: Before use, carefully check the expiry date on the tuberculin PPD-S vial to ensure the solution is still valid.
- Verify Contents: Make sure the vial contains tuberculin PPD-S with the concentration of 5 TU (Tuberculin Units) per 0.1 ml.
- Draw Solution: Draw the correct dose of PPD solution (0.1 ml) into the syringe.
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Administer the Injection:
- Intradermal Injection: Inject the tuberculin solution using a small-gauge needle into the upper layers of the skin (intradermally).
- Angle: The needle should be inserted at a shallow angle (typically around 5-15 degrees) just under the skin surface.
- Technique: Make sure the bevel of the needle is facing up. Inject the fluid slowly to create a small, pale elevation (a wheal) on the skin surface.
- Avoid Subcutaneous Injection: Be careful not to inject too deeply into the subcutaneous tissue, as this will affect the accuracy of the results.
- Intradermal Injection: Inject the tuberculin solution using a small-gauge needle into the upper layers of the skin (intradermally).
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Post-Injection Check:
- Visual Inspection: Observe the injection site immediately after administration to ensure that a wheal has formed. This indicates proper intradermal placement.
- Avoid Bandaging: Do not apply a bandage to the site as this could affect the reading later.
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Documentation:
- Record Information: After the test, accurately record the following:
- Date and time of administration
- Name of the tuberculin solution used (e.g., PPD-S)
- Batch number of the solution
- Dosage (typically 0.1 ml)
- Injection site location
- Name of administering personnel
- Record Information: After the test, accurately record the following:
Important Considerations
- Training: Administering PPD tests requires proper training and technique.
- Proper Handling: Always handle tuberculin solutions with care, observing appropriate infection control measures.
- Reading Results: The injection site needs to be assessed after 48–72 hours by trained personnel for any induration (hardening), which is indicative of a positive reaction. The test result is measured by the size of the induration, not the redness at the injection site.
