The Significance of the quantitative intradermal tuberculin reaction in the prognosis of tuberculosis

Abstract

Summary From the results obtained with the intradermal tuberculin test in the tuberculous and in the control series of cases, one is led to believe that the earlier the stage of disease and the less the degree of infection, a positive reaction can be obtained with a greater dilution of tuberculin. As the disease advances the patient fails to react to the greater dilutions, and lesser dilutions are necessary before a positive reaction can be obtained. Further, it becomes apparent that the intradermal tuberculin test in tuberculosis, when repeated at intervals, shows a more marked reaction when the case is improving, and fails to appear or become positive when a lesser dilution is employed when the case is retrogressing. It is thus a guide as to progress in addition to the clinical findings. A test which becomes more marked in reaction, e.g., from + to ++ or + + + , gives an indication that the lesion is improving and is of good prognostic value, whereas when a patient fails to react to the original dilution of tuberculin used and repeatedly fails to react with a lesser dilution, then the outlook is not hopeful.