Tuberculin Skin Testing in Young Children

Age-Based Recommendations

• The Centers for Disease Control and Prevention recommends that HIV-infected children should begin annual Mantoux tuberculin skin testing at age 3-12 months using intradermally injected 5 TU purified protein derivative (PPD) 1
• Children younger than 4 years of age are considered at increased risk for tuberculosis and warrant PPD testing with a positive cutoff of ≥10 mm induration 2

Critical Clinical Considerations

• The American Academy of Pediatrics notes that false-negative reactions occur more frequently in infants and young children, particularly early (<6-8 weeks) after infection, due to immature cellular immune responses 4
• Children aged <2 years or those with HIV infection are more likely to have negative skin tests even when infected with tuberculosis 1

Interpretation of Test Results

• Among children and adults with HIV infection, >5 mm of induration is considered a positive (diagnostic) reaction 1
• For children younger than 4 years who are contacts of TB cases or have other risk factors, >10 mm induration is considered positive 2

Common Pitfalls to Avoid

• The Centers for Disease Control and Prevention recommends that only the Mantoux method with intradermal injection should be used for TB skin testing, and not multiple puncture TB skin tests (e.g., Tine tests) in any age group 1
• Approximately 10% of children without HIV infection but with culture-positive TB disease do not react initially to TST, and a negative PPD should not rule out tuberculosis disease in young children 1