Qualitative evaluation of tuberculin test responses in childhood tuberculosis.

OBJECTIVE: To study if different forms of clinical presentation of tuberculosis in children are associated with a different type of tuberculin reaction. METHODS: This cross sectional study, describing Tuberculin skin testing (TST) responses in 268 children (134 cases and 134 controls) less than 12 yr of age was carried out over a period of 18 months at JIPMER, a tertiary care referral hospital in Pondicherry, India. The qualitative and quantitative TST responses in various clinical forms of Tuberculosis were analysed. RESULTS: Koch's and Listeria variants were more common in children with TB Lymphadenitis and Pulmonary TB respectively. 10% of the study children with TB meningitis were tuberculin negative. CONCLUSION: Qualitative TST responses are non-homogeneous among the various clinical types of childhood tuberculosis. They are not a correlate of protective immunity with little or no prognostic significance.