ANAPHYLAXIS 



193 



o.oi to 0.3 c.c. when given intravenously or intracardially and i or 2 c.c. 

 when given subcutaneously. 



This phenomenon of sensitization in the case of rabbits bears the 

 name of Arthus, and as applied to guinea-pigs sensitized with diphtheria 

 antitoxin sera the name Theobald Smith, and it is stated by Muir 

 and Ritchie that active research as to anaphylaxis may be said to date 

 from the discovery of the phenomenon of Theobald Smith. 



Rosenau and Anderson working with guinea-pigs showed that small 

 doses were efficient for sensitization, that the condition was trans- 

 missible from mother to offspring and that a second animal could be 

 sensitized by being injected with the serum of a sensitized animal. 



This group of symptoms, the so-called anaphylactic shock, which is apt to set in 

 within a few minutes after the second injection, is often preceded by restlessness 

 and great excitement and together with the dyspnceic manifestations such as cough- 

 ing and rapid breathing, there is cardiac weakness and great fall of blood pressure. 

 The more serious symptoms as convulsions and at times death in from a few minutes 

 to an hour are more apt to appear after intracerebral injections than after intra- 

 peritoneal. Subcutaneous injections are least apt to produce anaphylactic symp- 

 toms. Our attention to this phenomenon commenced with the study of "serum 

 sickness" or "serum disease." In this an erythematous rash or urticaria associated 

 with more or less oedema comes on after eight to twelve days from the time of the 

 first and only injection of horse serum. It is supposed to be due to the fact that 

 some of the serum originally injected remains unchanged in the tissues so that 

 when the sensitization takes place there is present and at hand the same foreign 

 proteid to bring about anaphylactic symptoms. 



Immunization against anaphylaxis is possible by repeating injection of the 

 sensitizing serum or proteid during the period of incubation. When a sensitized 

 animal recovers from the second injection it is afterward immune to anaphylaxis. 

 This is termed antianaphylaxis. 



It is important to note that this hypersusceptibility appears to be 

 very rarely of importance in the matter of the administration of a 

 second injection of diphtheria antitoxin after the period of anaphylactic 

 incubation. 



As a rule the death or untoward effects of the injection of serum are 

 in cases of status lymphaticus. Cases in man do occur, however, but 

 with extreme infrequency, in which within a few minutes after the 

 only injection of serum the patient becomes restless, shows symptoms 

 of cardiac and respiratory embarrassment and may be dead in a very 

 short time. 



According to Rosenau and Anderson individuals who have asthmatic tendencies 

 as well as those who have had serum injections ten to twelve days or longer prior 

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