Breakpoints for Interpretation of
Tuberculin Skin Test (TST) Results
 5 mm induration is interpreted as positive in the following circumstances:
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Child immunosuppressed (receiving immunosuppressive therapy or
immunocompromised, including HIV infection)
Child is a recent contact of a person with TB or suspected TB disease
Radiograph or clinical evidence suggestive of TB disease
Fibrotic changes on chest x-ray consistent with prior TB
 10 mm induration is interpreted as positive in the following circumstances:
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Child younger than 4 years of age
Child with medical conditions such as:
 Lymphoma
 Hodgkin’s disease
 Diabetes mellitus
 Chronic renal failure
 Malnutrition
Child or parent born in a country with a high prevalence of TB
Frequent exposure to high-risk adults, including adults who are HIV
infected, homeless, residents of nursing homes, institutionalized,
incarcerated, users of illicit drugs or migrant farm workers
Child with travel to high prevalence countries
All California residents
 15 mm induration is interpreted as positive in the following circumstance:
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Child 4 years or older with no risk factors and who are not residents of
California
From Pediatric Tuberculosis: An Online Presentation by Ann Loeffler, MD.
Produced by the Francis J. Curry National Tuberculosis Center.