Tuberculosis Skin Test (PPD Skin Test) (cont.)
Melissa Conrad Stöppler, MD
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
William C. Shiel Jr., MD, FACP, FACR
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
In this Article
- What is the tuberculosis skin test?
- How is the tuberculosis skin test administered?
- What is the method of reading the tuberculosis skin test?
- How are skin test results interpreted?
- Are there any risks from having the PPD skin test?
- Tuberculosis Skin Test At A Glance
Are there any risks from having the PPD skin test?
There is a very slight risk of having a severe reaction to the test, including swelling and redness of the arm, particularly in people who have had tuberculosis or been infected previously and in those who have previously had the BCG vaccine. Allergic reactions are also rare complications.
Live bacteria are not used in the test, so there is no chance of developing tuberculosis from the test.
Tuberculosis Skin Test At A Glance
- The tuberculosis skin test is also known as the tuberculin test or PPD test.
- The PPD test is used to determine if someone has developed an immune response to the bacterium that causes tuberculosis (TB).
- The standard recommended tuberculin test is the Mantoux test, which is administered by injecting a 0.1 mL volume containing 5 TU (tuberculin units) PPD into the top layers of skin of the forearm.
- Skin tests should be read 48-72 hours after the injection.
- The basis of the reading of the skin test is the presence or absence and the amount of induration (localized swelling).
- A negative test does not always mean that a person is free of tuberculosis.
- A person who received a BCG vaccine (administered in some countries but not the U.S.) against tuberculosis may also have a positive skin reaction to the TB test.
Herchline, Thomas, and Judith K. Amorosa. "Tuberculosis." eMedicine.com. May 18, 2010. <http://emedicine.medscape.com/article/230802-overview>.
Switzerland. "Global Tuberculosis Control: A Short Update to the 2009 Report." World Health Organization. <http://www.who.int/tb/publications/global_report/en/index.html>.
United States. Centers for Disease Control and Prevention. "Tuberculin Skin Testing." June 1, 2009. <http://www.cdc.gov/tb/publications/factsheets/testing/skintesting.htm>.
Last Editorial Review: 6/6/2011
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