HYPER8USCEPTIBILITY 367 



period after first injection is less than eight days, while in about 

 14 per cent it is longer than twelve days. 



The symptoms of serum sickness usually consist of an eruption 

 at the site of injection, which ordinarily comes on quite early, some 

 time before any general eruption is noticed. It often takes an 

 urticaria! form, and becomes general after several days. There is 

 usually some fever, occasionally albuminuria, and there may bo 

 joint manifestations. The joint manifestations are often of a 

 peculiar nature, with slight tenderness, but considerable stiffness, 

 and very little, if any, objective symptoms of the joints, and we 

 remember distinctly a case in which it was difficult to tell whether 

 or not the patient, who had received tetanus antitoxin ten days 

 before, was developing tetanus or not. The case turned out to be 

 one of serum sickness. Serum sickness may also be accompanied by 

 leucopaenia, aild, according to Weil, 51 by drops in blood pressure 

 and decreased coagulability of the blood. The latter manifestations, 

 as Wells points out, bring it still closer to true anaphylaxis. 



When a human bring is being treated for the second time with 

 horse serum at intervals longer than two or three weeks, the re- 

 semblance to true anaphylaxis is still greater, and as Doerr points 

 out, the procedure is more dangerous and will vary in its mani- 

 festations, according to the length of time elapsing between the two 

 injections. If the injections are not very much more than a month 

 apart, there may be, according to Von Pirquet and Schick, an 

 immediate reaction, which takes the character of severe serum dis- 

 ease. At the point of injection there may be swelling and edema, 

 within twenty-four hours, with general symptoms such as those 

 described above but rather more severe, within one or two days. 

 If the injections are months and years apart, the onset, while usually 

 more rapid than at the first injection, is still likely to occur more 

 rapidly than when the antigen is given the first time. 



Van Pirquet and Schick, from the beginning, believed that serum 

 sickness was due to the reaction of antigen which had not yet dis- 

 appeared from the circulation of the patient at a time when anti- 

 bodies were already being actively formed. 



Opinions as to whether' scrum sickness is to be regarded as true 

 anaphylaxis or not, seem to differ at the present time. Coca par- 

 ticularly seems to hesitate about incorporating these phenomena into 



ri n cil, Jour. Immimol., 2, 1917, 399. 



