20, 8 Gomez, Navarro, and Kapunan: The Schick Reaction 325 
Sharp and were introduced with the beveled surface toward the 
epidermis, and when there were no leaks in the syringes. 
INTERPRETATION OF THE REACTION 
The positive Schick reaction was shown by the appearance 
around the site of injection of a clearly defined area of redness 
and infiltration which lasted more than one week, leaving more 
or less pigmentation which disappeared usually in about a couple 
of weeks. In some cases the reaction was so marked as to 
produce sudaminiform eruptions, superficial necrosis, and blis- 
ters which desquamated on drying and left deep pigmentations 
for a considerable length of time (Plates 1 to 3). The nega- 
tive reaction was judged by the entire disappearance of the 
redness and tumefaction, due to traumatism of the injection, 
inside of two days, leaving at most a small pigmented point 
at the site of the entrance of the needle. 
Pseudoreaction, which was manifested by a less-defined area 
of redness and infiltration, disappearing usually inside of two 
days, was frequently noted; in adult subjects it at times lasted 
longer, leaving a small reddish pigmented area at the end of one 
week which was difficult to distinguish, in many cases, from true 
reaction, unless the test was properly controlled (Plate 4). 
The pseudoreaction occurred very seldom in young children, and 
what positive reaction they showed was so typical that later 
on no control injections were made on children below 4 years 
of age, as they were considered unnecessary. 
Inspection of the injections was usually made at the end of 
one, two, and three days, and one week, and the reactions that 
were considered doubtful were repeated, using different methods 
of control. There was no difficulty in passing judgment on 
strong positive reactions, but in those cases in which the re- 
action was weak or doubtful, careful comparison with control 
was made from day to day; and if, at the end of one week, the 
site of the unheated toxin definitely showed more pigmentation 
than the control, the reaction was considered positive. 
SUMMARY AND DISCUSSION OF FINDINGS 
The findings are shown in Table 1. In all 1,030 individuals 
of various ages were tested: 698 males and 332 females. 
Righty-eight, or 8.5 per cent, of the 1,030 people examined 
were positive. The table shows that most of the positives were 
found during the first eight years of life, especially during 
early infancy and childhood. The number of positives de- 
