THE SERUM DISEASE IN MAN 563 



the first injection, will lead to its combination and thus to its 

 being used up, and thus the condition of anti-anaphylaxis will 

 be established. 



It is still an open question as to what extent the phenomena 

 of anaphylaxis just described are of the same nature as the 

 supersensitiveness manifested by patients suffering from disease 

 to the products of the corresponding organism, e.y. to tuberculin, 

 mallein, etc. (pp. 284, 314) ; though in all probability they are at 

 least similar in essence. It was held for some time as a distinc- 

 tion that this s u pel-sensitiveness in infections to bacterial products 

 could not be transferred to another animal, but recent observa- 

 tions show that in certain circumstances this is possible in the 

 case of tuberculin. There is no doubt that the supersensitive 

 condition must play an important part in the clinical manifesta- 

 tions of many diseases. For example, the sensitiveness of 

 tubercular patients to tuberculin shows that the symptoms in 

 this disease are evidently produced by the absorption from the 

 tubercular foci of a smaller amount of toxin than would be 

 necessary to produce effects in a normal individual. And the 

 sensitiveness of the conjunctiva in typhoid fever to the products 

 of the bacillus suggests that in this disease also supersensitive- 

 ness plays an important part. It is also possible that the 

 repeated absorption of proteins, harmless in single doses, may 

 I fat I to toxic symptoms, and in a similar way may possibly be 

 explained the relative non-toxicity of the products of certain 

 bacteria when tested in the usual manner. But with regard to 

 all these questions, which are of the highest importance, much 

 further research is still necessary. 



The Serum Disease in Man. This condition, which is 

 intimately related to suj>ersensitiveness, includes the phenomena 

 which have been observed after the injection of anti-diphtheric 

 and other sera. The real factor is the introduction of foreign 

 sera into the human tissues. As in the case of anaphylaxis, as 

 above described, there is here also a period of incubation, of eight 

 to twelve days on the average ; after which, in a certain proportion 

 of cases (in about 20 per cent, after the injection of a fairly 

 large amount of horse serum, a group of characteristic symptoms 

 appear. There may be as prodromal symptoms, swelling and 

 tenderness at the site of injection, and in the corresponding 

 lymphatic glands, and thereafter general exanthemata appear. 

 These are usually of an urticarial type, but may be erythematous 

 or morbilliform. There is usually moderate pyrexia of a 

 remittent type, and sometimes cedema and slight albuminuria 

 are present ; occasionally there are pains in the joints ; there is 



