Value of the tuberculin patch test in case finding

Abstract

<h2>Summary</h2> The value of the tuberculin patch test in case finding has been studied in three groups of children, totalling 2,000 cases. Among 847 children admitted to the Mount Sinai Hospital, there was only one case with clinical, roentgenographic, or bacteriologic findings indicating a tuberculous infection which failed to show a positive reaction to the patch test. This exception was a child with miliary tuberculosis in whom the Mantoux test with 1.0 mg. of old tuberculin was also negative. Among 540 children in the Sea View Hospital, 535 had active tuberculous lesions, and 529 of the latter were positive to the patch test. Of the six cases who failed to react to the patch test, four were known to be negative anergic and also to show negative reactions to the Mantoux test with high tuberculin concentrations. Only two cases were really missed by the patch test; one of them was a child with anergy who reacted only to the Mantoux test with second strength purified protein derivative. A mass examination of 613 high school students was carried out by the New York Health Department with the Mantoux test, the patch test, and x-ray examinations. No significant lesions were missed if patients failed to react positively to either the patch or Mantoux test. Among 2,000 children with 763 positive reactors to tuberculin, three cases with active tuberculosis were missed by the patch test, one of which was missed also by the Mantoux test with 1.0 mg. of old tuberculin. Two of the failures cannot reasonably be ascribed to an insufficiency of the patch test but rather to the biologic character of the tuberculous condition, miliary tuberculosis and positive anergy, respectively. From this survey, the tuberculin patch test appears to be sufficiently reliable for case finding. A survey of the literature on the patch test is given, including several personal communications. Ten different investigators made comparative studies in 4,285 cases and found, 1,114 positive reactors to the patch test as compared with 1,119 positive reactors to the Mantoux text. These results agreed with those reported by the author. In a total of 6,104 cases, 1,819 were positive to the patch test, and 1,833 to the Mantoux test including the use of higher tuberculin concentrations. The average difference was 0.77 per cent in favor of the Mantoux test. There was 100 per cent agreement between the number of positive reactors to the patch test and positive reactors to the Mantoux test with 0.1 mg. old tuberculin or first strength purified protein derivative. In contrast to this favorable evaluation of the patch test, Peck and Wegman found 28.3 and 70.5 per cent discrepancy, respectively, when the Mantoux test using first and second strength purified protein derivative was compared with the patch test. The reasons for these findings are not known. The possible errors are enumerated. In order to avoid too strong reactions to the patch test in cases of active tuberculosis, a preliminary patch test can be carried out which is applied for only six to twenty-four, instead of forty-eight hours.