SERUM SICKNESS 141 



" immediate reaction " described by von Pirquet 

 and Schick, in which second injection of a serum 

 produces an attack of serum sickness without any 

 period of incubation. This includes also some of 

 the cases of sudden death following the injection 

 of horse serum. Here the second injection comes 

 at a time when the accumulation of antibodies is 

 at its height. Similar results were obtained in- 

 dependently by Rosenau and Anderson, 1 who found 

 in the case of guinea pigs, that horse serum is poi- 

 sonous to such animals as have been previously 

 injected with small amounts of horse serum. 2 The 

 time necessary to elapse between the first and sec- 

 ond injections is about ten days. The symptoms 

 are respiratory embarrassment, paralysis and con- 

 vulsions, and come on usually within ten minutes 

 after the injection. When death results it usually 

 occurs within one hour, frequently in less than thirty 

 minutes. The poisonous principle in horse serum 

 appears to act on the respiratory centers. The 

 heart continues to beat long after respiration ceases. 

 The first injection of horse serum renders the 

 guinea pig susceptible; the quantity required for 

 this purpose is extremely small. Rosenau and 

 Anderson find that from ^ to ToW c.c. ordinarily 

 suffice. One tenth c.c. of horse serum injected into 



1 Rosenau and Anderson, Bulletin 29, Hygienic Laboratory, 

 Washington, 1906. 



2 The Germans usually speak of this as " Theobald Smith's 

 phenomenon of hypersusceptibility." 



