To the Editor
—The tuberculin test remains a useful aid in the diagnosis of tuberculosis. While today's low prevalence of tuberculosis has rendered screening by PPD to be of questionable value, it can be of considerable importance if one thinks of tuberculosis as a possible cause of a patient's illness. Israel et al, in the November Archives (1981;141:1723), advocate uniform documentation of skin test results in the patient's medical record. We could not agree more and see no reason that erratic administration and shoddy interpretation of the test should be allowed to interfere with the potential information that is to be gained from this test.It has been our experience, similar to that of Israel et al, that there is one ongoing need for standardization and quality control. Improper injection is probably an overrated cause of error.1 Published standards for interpretation of the various skin tests used to assess