140 ANAPHYLAXIS, ALLERGY OR HYPERSENSITIVENESS 



occasionally succumbed to a subsequent small dose of the homologous 

 toxin, although the blood serum of these animals contained much 

 specific antitoxin. 



2. Serum Sickness or Serum Disease. Attention was first directed 

 to serum sickness by von Pirquet and Schick, 1 who noticed that there 

 occasionally developed in individuals who had received an injection 

 of antitoxic sera, usually after seven to fourteen days, fever and a 

 rash which might be urticarial, scarlatinal, or, in the more severe 

 cases, morbilliform ; enlargement of lymph glands, particularly those 

 near the site of inoculation; and joint pains, more frequently of the 

 metacarpal joints. A slight edema, frequently of the angioneurotic 

 type, was also occasionally observed. The fever is usually slight 

 and there are signs of respiratory embarrassment, not as a rule 

 marked, but occasionally severe. These reactions, sudden death 

 and serum sickness, are more common in asthmatics, and in those 

 individuals presenting the pathological syndrome known as status 

 lymphaticus. 



According to Moschowitz, 2 these individuals, particularly the 

 asthmatics, present an eosinophilia. The exact cause of sudden death 

 following the administration of diphtheria antitoxin is not definitely 

 known, but it has been assumed that respiratory involvement is a 

 potent factor. The appearance of serum disease seven to fourteen 

 days after the administration of antitoxin is supposed to depend upon 

 the fact that some of the alien protein (serum) remains in the body 

 during the period of pre-anaphylaxis (period of sensitization) , and 

 that this residual protein is broken down by the mature specific enzyme 

 or enzymes with the liberation of a poisonous substance which causes 

 the anaphylactic shock. 



3. Arthus Phenomenon. During the course of immunization against 

 rabies by the Pasteur method it is frequently noticed that after three 

 or four injections a subsequent injection causes symptoms of inflam- 

 mation at the site of the first injection, and that this phenomenon is 

 repeated, usually, but not always, with diminishing intensity at the 

 site of earlier injections as the treatment progresses. This -inflam- 

 matory reaction at the site of injection is not due to bacterial infection 

 ordinarily, but is rather an expression of anaphylaxis. It is comparable 

 to the Arthus phenomenon produced in rabbits by successive injec- 

 tions of serum referred to above. Also in revaccination (vaccinia) 

 a so-called accelerated reaction may occur the second time the indivi- 



1 Die Serumkrankheit, Leipzig, 1905. 



2 New York Med. Jour., 1911, Ixxxxiii, 15. 



