The tuberculin skin test is used to determine whether a person has TB infection. The Mantoux tuberculin skin test is the preferred type of skin test because it is the most accurate. Whether a reaction to the Mantoux tuberculin skin test is classified as positive depends on the size of the induration, the person's risk factors for TB, and for people who may be exposed to TB on the job, the risk of exposure to TB in the person's job.
Several factors can affect how the skin test reaction is interpreted.
Two-step testing is a strategy for telling the difference between boosted reactions and reactions caused by recent infection. A medical history includes asking the patient whether they have been exposed to a person with TB, symptoms of TB disease, if they have had TB infection or TB disease before, or risk factors for developing TB disease. The symptoms of extrapulmonary TB disease depend on the part of the body that is affected by the disease. Patients with symptoms of TB disease may be given a tuberculin skin test . They should be evaluated for TB disease, regardless of their skin tests results.