It has been noted by several observers that the Schick reaction is unreliable in new-born infants. Infants, born of mothers who gave a positive reaction to the Schick test, who have no demonstrable antitoxin in their blood fail in a large percentage of instances to give a positive reaction to the Schick test.
Von Groer and Kassowitz1 found that only seven infants of twenty-three who had been shown to have no antitoxin in their cord blood gave positive reactions when tested intradermally. Thus, 70 per cent failed to react. In Ruh and McClelland's2 series of twenty-four infants born of mothers giving positive reactions to the Schick test, four, or 17 per cent, gave a negative skin test. In Kuttner and Ratner's3 eleven cases, seven, or 64 per cent, failed to react.
It is obvious that the number of infants observed by these authors is too small to