CHAPTER XII 



ANAPHYLAXIS 



Definition of anaphylaxis — Experiments of Richet and Portier — Anaphylaxis 

 to various poisons — Anaphylaxis to normal serum — Arthus' phenomenon 

 — Serum sickness : observations of V. Pirquet and Schick — Serum 

 anaphylaxis in guinea-pigs ; phenomenon of Th. Smith — Anaphylaxis 

 to cells and organ extracts — Passive anaphylaxis. 



Study of Richet's poisons and serum anaphylaxis — Anti-anaphylaxis 

 (Besredka) : not a vaccination — Application to serotherapy — Heating 

 of sera — Theories of anaphylaxis — feeneral theory of antibodies. 



Anaphylaxis is the opposite of vaccination. An animal is 

 vaccinated vsrhen the first attack by a virus (microbe or toxin) 

 produces in it changes through which it is protected against 

 another more serious attack. If you suppose the animal to 

 become, after the first attack, not more resistant, but more 

 susceptible, you have in a word the root idea of anaphylaxis. 



The paradox is even greater than this definition shows, for 

 anaphylaxis exists not only towards viruses against which 

 immunity also occurs, but also it appears towards substances 

 which in the normal individual are apparently quite innocuous, 

 for example, egg-white, milk, and serum. In this way the 

 first injection with these substances, instead of producing 

 immunity, seems to destroy the natural immunity of the normal 

 animal. 



The supersensitiveness produced by a first inoculation and 

 brought to light by a second is not due to a cumulative action, 

 such as may be observed after several successive doses of 

 certain drugs ; in anaphylaxis the effect is out of all proportion 

 to the quantity of material ingested. 



