PROTEIN SENSITIZATION OR ANAPHYLAXIS 247 



within a few hours. The stage of peripheral irritation is 

 characterized by the sudden appearance of a rash. The 

 rashes that occur most promptly are urticarial or erythema- 

 tous. We have seen such a rash rapidly spread over the 

 surface like a blush in every direction from the point of 

 injection, and soon involve the entire surface. The lips and 

 tongue seem swollen, and often the backs of the hands are 

 swollen. The individual becomes apprehensive, says that 

 he cannot breathe, and falls into a state of more or less 

 marked collapse. In extreme instances there is retching, 

 and occasionally vomiting. The second stage, that of 

 great muscular weakness, continues for a variable time and 

 usually rapidly passes away. In rare instances speedy 

 death results. 



The Mechanism of Anaphylaxis. Gay and Southard 1 

 were the first to study the pathological changes induced 

 by anaphy lactic shock in guinea-pigs. They reported 

 minute hemorrhages in the pleura and in the mucous mem- 

 brane of the stomach, and showed that the lungs are inflated 

 after death. Auer and Lewis 2 made plain that death in 

 guinea-pigs from anaphylaxis is not due to effects on the 

 central nervous system, but is due to tetanic contraction of 

 the smooth muscles of the bronchioles. They also demon- 

 strated that these spasms could be averted and life saved 

 by preventive injections of atropine. These findings have 

 been fully confirmed by subsequent researches, especially 

 those of Biedl and Kraus. It is to the last-named investi- 

 gators that we owe the most complete and satisfactory 

 demonstration of the mechanism of anaphylactic shock. 

 Biedl and Kraus 3 have summed up their own and the 

 researches of others on this point up to the time of their 

 writing (1910). We will first follow the summary and then 

 review the work done since that time. 



In dogs, fall in blood pressure is a characteristic and 



1 Jour. Med. Research, 1908. 



2 Jour. Amer. Med. Assoc., 1909. 



3 Kraus and Levaditi, Handbuch d. Technik u. Methodik d. Immuni- 

 tiitsforschung, Erganzungsband, i. 



