The advantages of the tuberculin patch test are obvious: It is absolutely painless and hence eliminates the elements of fear, wherefore it is especially adapted for testing children; it requires no lancets or borers (as in the Pirquet1 test), no syringes and needles (as in the Mantoux2 test) and no rubbing of tuberculin ointment into the skin (as in the Moro3 test).
The long-felt need of a simple and painless method of testing for tuberculosis evidenced itself by the numerous publications dealing with the tuberculin patch test and by its wide acceptance.
The patch test, however, has one disadvantage when compared with the Pirquet, Mantoux and Moro tests: The area of reaction remains concealed while the patch is in place, so that it cannot be followed during the phases of its development. In other words, the test is a "blind test."
DISADVANTAGES OF A "BLIND TEST"