The usual method of tuberculin skin reaction measurement of induration is palpation. Unfortunately, even skilled examiners may have considerable difficulty in identifying or measuring induration by this method. A 2 percent error in the measurement decreases the accuracy of the method by 25 percent, exceeding 50 percent for a 5 percent error. The measurement of tuberculin skin reaction by the pen method has been suggested as a superior alternative, since it can be used by less experienced observers.
In two previously published studies comparing the two methods in 135 bacteriologically-proven tuberculous patients and in 806 healthy volunteers, the results were controversial.
We, therefore, undertook a prospective, doubleblind study to compare the degree of concordance of the above two methods in a large number of recruits entering a BCG vaccination program at their enrollment in the Greek Army.
Subjects and Methods
Wfe performed tuberculin skin testing utilizing the Mantoux technique in 1,340 male recruits in the Greek Army, aged 18 to 25 years (mean 20 years), entering in a BCG vaccination program. After informed consent, 2IU of PPD-RT 23 (1/5,000) of the Pasteur Institute, approximately equivalent to 5 TU of PPD-S, was administered intradermally on the volar aspect of the forearm.