Our study was designed specifically to assess the reliability of the measurement of skin induration obtained after tuberculin skin testing. We could not agree more with the recommendations of Dr. Flynn; of course, as stated in our article, the proper administration of the tuberculin skin test according to the Mantoux technique was a prerequisite of our study. It is undoubtedly essential to administer the tuberculin skin test in the proper way. Moreover, in addition to administering the test correctly and measuring the skin induration carefully, it should be emphasized that the interpretation of the tuberculin skin test result should consider the individual clinical context and the official published recommendations on tuberculosis [1]. Again, although useful, the tuberculin skin test remains an imperfect diagnostic tool and should not replace clinical judgment.

We apologize to Longfield and colleagues for having omitted their study from our article and agree that the picture of the ballpoint method they presented may be useful to readers [2]. As in our study, interobserver reliability appreciated by global coefficients indicated good agreement (0.82 for the ballpoint method and 0.84 for palpation). Unfortunately, Longfield and colleagues did not use the graphical analysis recommended by Bland and Altman, which provides a more meaningful representation of the level of variation [3]. Although we agree that the overall percentage of patients who would have reclassification of their tuberculin skin test result is rather low (7% between the ballpoint and palpation methods by the same reader in Longfield and colleagues' study and 12% to 17.4% in our study according to the technique of measurement and the interobserver or intraobserver analysis), misclassification may be much more common when measurements are close to the cutoff point that separates negative from positive results.