A comparative study of the old tuberculin tine test and the PPD-tine test

Forty-one children suspected of having tuberculosis were simultaneously given an intermediate strength Mantoux test, an old tuberculin tine test (OT), and a purified protein derivative (PPD) tine test. Each test was read at 48 hours, and the largest diameter of induration was recorded. Twenty-nine patients had a positive reaction to the Mantoux test, 20 patients had a positive reaction to the OT tine test, and 16 patients had a positive reaction to the PPD-tine test. There were seven instances of a doubtful reaction to the OT tine test and nine to the PPD-tine test. Two children with positive Mantoux tests had negative OT tine tests, and four with positive Mantoux tests had negative PPD-tine test reactions. There was a significant difference between the number of positive reactors to the Mantoux test and both tine tests. If all tine test reactions of 2 mm or more were considered positive (doubtful plus positive reactors), there was no significant difference between any of the tuberculin tests. All suggestively positive tine reactors should, therefore, be retested with a Mantoux test to avoid false-negative interpretation of the tines.