The clinic nurse reads the results of a tuberculin skin test (TST) on a 3-year-old child. The results indicate an area of induration measuring 10 mm. The nurse should interpret these results as which finding?

PositiveNegativeInconclusiveDefinitive and requiring a repeat test

Explanation.

Induration measuring 10 mm or more is considered to be a positive result in children younger than 4 years of age and in children with chronic illness or at high risk for exposure to tuberculosis. Areaction of 5 mm or more is considered to be a positive result for the highest risk groups, such as a child with an immunosuppressive condition or a child with human immunodeficiency virus (HIV) infection. A reaction of 15 mm or more is positive in children 4 years or older without any risk factors.