ANAPHYLAXIS IN MAN 141 



dual is vaccinated. This accelerated reaction again is a mild edition 

 of the Arthus phenomenon. 



4. Prophylaxis. At first sight it might appear that the administra- 

 tion of diphtheria and tetanus antitoxin for therapeutic purposes would 

 be a dangerous procedure. If there is reason to suspect that the 

 patient would react to the injection of antitoxin it is advisable to 

 inject 0.1 or 0.2 c.c. subcutaneously and wait half an hour. If no 

 symptoms develop, the full dose may be given without danger; it 

 is generally believed that even if mild symptoms do follow the initial 

 injection, the full dose may be given with safety after half an hour; 

 the first injection appears to abort what otherwise might be a reaction 

 dangerous to the patient 



The present method of concentrating diphtheria antitoxin by frac- 

 tional precipitation of the globulin 1 appears to reduce very materially 

 the incidence of serum sickness. According to German investigators, 

 antitoxin which has stood for one or two months has lost to a very 

 considerable extent the substance or substances which cause the 

 symptoms of serum sickness. 



Practical and Theoretical Considerations. A. Advantage is taken 

 of the sensitization of individuals by bacterial protein during certain 

 bacterial infections, particularly those with the tubercle bacillus, 

 B. mallei, and in syphilis, for diagnostic purposes. It has been shown 

 almost beyond doubt that individuals suffering from these diseases are 

 sensitized to the bacterial protein, and it is possible to make a fairly defi- 

 nite clinical diagnosis by introducing extracts of the specific organisms 

 into the skin and inducing there an anaphylactic reaction which, if the 

 dose is small, is local in character, but which may be general and severe 

 if the dose is increased in amount. The von Pirquet, Calmet, Moro, and 

 Koch methods of utilizing tuberculin for diagnostic purposes are directly 

 dependent upon this reaction of hypersensitiveness. The diagnostic 

 use of mallein and luetin depend upon the same phenomenon. 



B. Advantage is also taken of the specificity of the anaphylactic 

 reaction for the recognition of proteins. Wells and Osborn 2 and 

 many others have sensitized guinea-pigs with proteins and then 

 injected into these sensitized animals proteins which are to be iden- 

 tified either specifically or phylogenetically. The nature and extent 

 of the anaphylactic reaction in these animals furnishes the most deli- 

 cate test (except possibly the precipitin test) which is available for 

 such investigations. 



1 Banzhof, Johns Hopkins Hosp. Bull., 1911, xxii, 241. 



2 Loc. cit. 



