Mantoux Tuberculin skin testing by wulinqing


Tuberculin skin testing
Andrea Jurgrau, CPNP
Joan Coetzee CPN, PN
Field Representatives
for the P1078 team
CDC TST guidelines

 P1078 uses CDC guidelines for TST
 The guidelines can be found at the
  CDC website, as can training material
  and supplies:
 The P1078 MOP has an overview of
  these guidelines.
What is a TST?
   A tuberculin Skin Test (TST)
   The technique we are using in the Mantoux
   This is a intradermal injection of Protein
    Purified Derivative (PPD)
   It tests for exposure to Tuberculosis (TB)
    also known as latent TB
   Because it is a delayed immune response, it
    takes 48-72 hours for the reaction to take
    place and the TST to be read and
Materials for administering
the TST
   PPD 5tu* unit dose vials for intradermal
   Single use, disposable TB syringe and ½
    inch 27 gauge short bevel needle.
   Alcohol pads.
   Tuberculin skin test ruler (plastic ruler with
    mm rule.)
   Refrigerator for long-term storage at 2-8
    degrees C and a cooler for use in the clinic
    if vial can’t be returned to refrigerator
            Preparing to Place TST
   Wash hands and put on gloves. If no water is available, use an appropriate skin-
    cleaning product (e.g., an alcohol based hand cleaner).
   Check PPD vial’s expiration/opening date. If it has been open for more than 30
    days, discard the vial and get a new one. Be sure you review proper storage for
    vials between use.
   Place patient’s arm on a flat surface, exposing the volar (inside) surface of the
   Locate site for the injection (2-4 inches below elbow, where no scars, bumps or
    veins are located).
   Clean the injection site with an alcohol swab and allow it to dry before applying test.
   Wipe the top of the PPD vial with a second alcohol swab and place the vial on a flat
   Prepare the syringe by inserting it into the vial. Inject 0.1 ml of air into the airspace
    in the vial. Do not inject air into the PPD solution.
   Invert the vial, keeping the needle tip below fluid level.
   Pull back on the plunger of the syringe and draw slightly more than 0.1 ml of PPD
   Remove the syringe from the vial and tap the syringe lightly to dispel air bubbles.
    Hold the syringe point up and expel air and/or excess fluid, leaving exactly 0.1 ml of
    PPD solution in the syringe.
   Return the PPD vial to the refrigerator when not in use and place on a cooling pad
    when in use. Protect the vials from light.
            Placing TST

   NOTE! interferon gamma blood collection has to happen first before
    TST placement for P1078
   Stretch the skin of the injection site with the thumb of the non-dominant
    hand (e.g., left hand for right-handed persons).
   Hold the syringe between the thumb and forefinger of the dominant hand,
    (e.g., right hand for right-handed persons) with the bevel of the needle
    pointing upward. Insert the needle intradermally (just under the top layer
    of skin) at a 5°-15° angle, with the bevel up. The bevel should be just
    below the skin, and the needle should be inserted about 3mm so the
    entire bevel is covered.
   Release the stretched skin, inject the PPD solution slowly. A firm
    resistance should be felt as the tuberculin solution enters the skin.
   Remove the needle from the injection site (DO NOT RECAP). Discard the
    syringe immediately in a sharps container.
Measuring TST after Placing

 Once you place the TST you must
  measure it right away to make sure it
  was done properly
 Use your ruler to measure the wheal.
  It should be at least 6mm in diameter.
 If it is not, repeat the TST at a new
  site at least 2 inches away from first
  site. Be sure you document the test
  was repeated.
       TST Patient Teaching
   Educate the patient on the possible reactions to
    the TST (e.g., mild itching, swelling, irritation).
   Instruct patient not to rub, scratch or put an
    adhesive bandage or lotion on the test site. The
    area may be washed and patted dry.
   Document the test in the patient’s CRF (including
    second test if done). Be sure to include location of
    test site in your documentation.
   Schedule reading date and explain the importance
    of the patient returning for reading in 48 to 72
Materials for reading TST

 Tuberculin skin test ruler (plastic ruler
  with mm rule.)
 Felt-tip pen

 Alcohol pads to remove pen marks
          Reading TST
   Read the result 48 to 72 hours after administering the test.
   Inspect the injection site for raised areas.
   Palpate the arm for a hard, raised area known as an induration.
    Feel the edges of the induration with the index finger
   Mark the 2 edges of the induration with a dot, using a black,
    watermark or felt-tip pen.
   Measure the induration (not redness) at its widest point
    transversely, from 1 marked edge to the other, using a flexible
    TST ruler. If the reading is between 2 points, the lower value
    should be used. Swollen areas, if they feel hard, (but not red
    areas) should be palpated and included in the measurement.
   Record the size in millimeters and not simply as “positive” or
    “negative”. If there is no induration, record the result as “00 mm.”
   Interpret the reaction as positive or negative based on the size of
    the induration being ≥5mm (for HIV+ study subjects)
   Explain the meaning of a positive or negative reaction to the
    individual and refer for follow-up evaluation, if needed.

   Vaccination with live attenuated viral
    vaccines such as measles, mumps and/or
    rubella (MMR) can cause a false-negative
    reaction to the TST. The TST can be
    administered on the same day as the live
    vaccine. If a skin test is needed, and was
    not given in conjunction with the
    vaccination, wait 4-6 weeks before
    administering a TST.
   If the patient fails to return for the scheduled
    reading but returns up to a week (7 days) after
    the test, examine the test site and measure
    any induration present; if it is large enough to
    be classified as positive, record the result. No
    further testing is needed. If there is no
    reaction, or the induration is too small to be
    classified as positive, repeat the test. A
    repeat test can be given immediately.

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