How to Read a Tuberculin Test

Tuberculin tests are administered to determine if a person has, or has been exposed to, tuberculosis. Purified protein derivative is injected under the skin by a licensed health professional and within 48 hours the site is read for a negative or positive reaction. If there is a positive reaction, additional tests must be performed to indicate whether the infection is active or inactive and how long the person has been infected.

Things You'll Need

• Licensed Health Professional
• Alcohol Swab
• Tuberculin syringe
• Tuberculosis Purified Protein Derivative
• Chair

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Instructions

• 1

  Select a tuberculin syringe and fill it with a small amount of the TB protein. Choose an injection site on the inner forearm of the sitting client.

• 2

  Wipe the site of the client with an alcohol swab and allow drying time. Once the site is dry, inject the TB protein with the syringe slightly under the top layer of skin creating a small bleb, which is a slight bubbling of the skin.

• 3

  Make a mental note of the site and advise the client to return within 48 to 72 hours for the site to be read. Inform the client to not bother or disturb the site, as this could interfere with the results.

• 4

  Read the site for a positive or negative reaction after a minimum of 48 hours. If the site is red without any other symptoms, then the client has not been infected with the Tuberculosis bacteria. If the site is red but also has a bump, varying in size, this is a positive reaction.

• 5

  Measure the bump, not the redness, two to three days after the test. The licensed health professional will determine your chances of having tuberculosis depending upon the test site. Additional tests, such as chest X-rays, may also be ordered to make the final tuberculosis diagnosis.