94 



Scientific Proceedings (90). 



intracutaneous injection of 0.1 c.c. of the toxin by a local erythema 

 and hemorrhagic edema in the subcutaneous tissue overlying the 

 muscle. The skin reaction to heat-killed pneumococci was nega- 

 tive in most of these animals and when positive, was of a suppura- 

 tive type, marked by less edema and more leucocytosis. Control 

 animals gave uniformly negative results. 



Among human adult cases of lobar pneumonia the reaction 

 (which was characterized by a local edema and erythema) was 

 elicited as early as the fifth and as late as the thirteenth day of the 

 disease (two days before and six days after the crisis, respectively). 

 In children it was demonstrable about the same time, but was 

 negative immediately or one or two days after the crisis. Patients 

 recovering by lysis reacted as late as the thirty-second day. 

 In general, the test was positive in all active cases, that is, through- 

 out the toxemia. Cases earlier than the fifth day of the disease 

 were not available. Control patients, suffering with broncho- 

 pneumonia or with acute or chronic infections not of pneumococcic 

 origin, as well as healthy adults and children did not react. 



The reaction is regarded as similar to the tuberculin reaction 

 and is indicative of a state of allergy to pneumotoxin. Sensitiza- 

 tion to the toxin presumably takes place with its liberation (by 

 the action of normal body enzymes upon pneumococci normally 

 localized in the lung alveoli) at the time of the prolonged chilling 

 due to exposure. Failure to elicit the reaction during convales- 

 cence indicates the establishment of a temporary immunity or 

 the disappearance of excess of toxin. This skin test does not seem 

 to be of value as a method of serological type diagnosis but may 

 aid in differential diagnosis between appendicitis or tuberculosis 

 and pneumonia (especially in children). It is also of interest 

 because of its bearing on the mechanism of the crisis. 



