CHAPTER LXXIII 

 ANAPHYLAXIS AND ANAPHYLACTOID REACTIONS 



HOWARD T. KARSNER 



School of Medicine, Western Reserve University, Cleveland, Ohio 



LIMITATION OF TERMS 



The response of vertebrates to the introduction of foreign substances either en- 

 terally through the ahmentary canal or parenterally through other channels is vari- 

 able in species and in the individual. This chapter is concerned principally with quan- 

 titative differences in individuals of a species and also in certain measure with differ- 

 ences both qualitative and quantitative in various species. 



HYPERSENSITIVENESS 



The usual response in a number of individuals within the species is spoken of as 

 normal, but the normal covers a certain generally accepted range of variability. Indi- 

 viduals who exhibit a greater response than is considered normal are referred to as 

 "hypersensitive." It is well known in pharmacology that certain individuals respond 

 more severely to certain drugs than do others, and thus they are literally hypersensi- 

 tive. Common experience shows that certain persons become poisoned by contact 

 with poison ivy and sumac whereas others are completely resistant; the former are 

 hypersensitive. Certain individuals respond to inhalation of plant pollens, animal 

 dander, and other organic particulate matter in the atmosphere by exhibiting asthma, 

 coryza, intestinal and other disturbances — materials which to the vast majority are 

 innocuous. When diphtheria antitoxin gained widespread use, it was found that sub- 

 sequent to injection most individuals develop a more or less severe "serum disease" 

 and that a few are immediately made seriously or even fatally ill. It was noticed that 

 the latter were either naturally hypersensitive or had acquired hypersensitiveness by 

 a previous injection of horse serum. The term "hypersensitiveness" thus covers a 

 variety of forms, some natural and some acquired, some to simple substances, some 

 to such highly organized materials as proteins. In the immunological sense, hyper- 

 sensitiveness is restricted to that which is inherent in or natural to the individual 

 and that which is acquired. Frequently the hypersensitiveness exhibited in derma- 

 titis venenata is also included in this category, but by common consent that observed 

 in response to drugs and inorganic materials is excluded. 



When these abnormal reactions had been studied. Von Pirquet and Schick^ sug- 

 gested the word "allergy" (alios, "altered"; ergia, "reactivity") as a comprehensive 

 term covering the various manifestations, more especially the alteration of reactions 

 in man as observed in the more rapid appearance of the manifestations of serum 



'von Pirquet, C. E., and Schick, B.: Munchen. med. Wchnschr., 53, 66. igo6; see also von 

 Pirquet, C. E.: Arch. Int. Med., 7, 259. 1911. 



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