Tuberculin reactivity in tuberculous meningitis

To study tuberculin reactivity in childhood tuberculous meningitis both in clinical and histopathological (HP) context.

Children with tuberculous meningitis (TBM) were given tuberculin test by Mantoux technique, which was read at the end of 72 hours after the placement of skin test. Histopathological examination of the punch biopsy specimen of the tuberculin test site was performed and histopathological grading of the tuberculin reaction was compared with clinical reaction and clinical parameters.

Of the 50 children studied, 68% of them were malnourished and 42% had BCG scar. Tuberculin test was positive in 22 (44%) cases. Spearman analysis showed negative correlation between stage of TBM and the size of tuberculin reaction. BCG status did not affect the size of tuberculin reaction. Histopathological grade of the tuberculin reaction was found to be directly proportional to the size of the tuberculin reaction and it was not affected by the stage of TBM.

Tuberculin positivity is low in TBM irrespective of the nutritional status. At least some degree of inflammatory reaction can be seen at the site of tuberculin administration. In tuberculin negative cases, varying grades of cellular response in the absence of clinical induration can be seen in histopathology.