HYPERSENSITIVENESS, PROTEIN INTOXICATION 223 



acute suffocation, asthma, terrific engorgement of the tissues of the neck 

 and chest with collapse and death. The latter picture is rare unless the 

 offending substance is introduced subcutaneously or intravenously, and 

 though very alarming symptoms have followed the taking by mouth of pro- 

 teins to which the patient is hypersensitive, death rarely, if ever, occurs 

 under these latter conditions. 



The etiology of this condition is still very obscure. At first sight and 

 in accordance with the experience obtained from experiments upon the 

 guinea-pig, it might seem to follow naturally that the mere parenteral 

 introduction of any foreign native protein in the normal individual would 

 be sufficient to explain the development of these extraordinary idiosyn- 

 crasies. It is highly probable indeed that foreign native proteins often 

 gain access to the body tissues either through artificial means, the method 

 which certainly occurs in therapeutic inoculations of foreign serum, or by 

 natural methods. It has, for instance, been shown by Schloss and 

 Worthen(a) and by Grules and Bonar that a fair proportion of infants 

 absorb egg albumen from the gastro-intestinal tract and excrete this protein 

 unchanged in the urine. Apparently the absorption of this protein un- 

 changed is much more likely to take place during acute and chronic gastro- 

 intestinal disturbances than under normal conditions, but Grulee and 

 Bonar have recently shown that many normal infants, free from gastro- 

 intestinal disturbances, may absorb and excrete egg albumen up to the 

 llth day of life. 



But it is obvious that only small quantities of foreign proteins could 

 come in contact directly with the tissues or the fluids of the body by this 

 method, and since it is known that man is much less readily sensitized than 

 many of the lower animals such as' the guinea-pig, it does not seem likely 

 that the absorption of foreign native proteins through the mucous mem- 

 branes of the gastro-intestinal tract or of the respiratory tract, or through 

 the skin can account alone for the exquisite sensitization which is often 

 observed in the human being. Even in the animals such as the guinea- 

 pig that lend themselves most readily to experimental sensitization, the 

 process is accomplished with much more difficulty when the foreign pro- 

 tein is applied to the mucous membranes than when it is injected beneath 

 the skin or into the peritoneal cavity or intravenously. 



Indeed, such a mechanism could not account for the exquisite hyper- 

 sensitiveness of the child who reacts by a violent attack of vomiting or 

 urticaria upon the first occasion when he is given egg by mouth, or for the 

 fact that the skin of certain individuals may show an extraordinary idio- 

 syncrasy towards a substance with which they could not previously have 

 come in contact. In many cases a third and important factor must be 

 taken into consideration, namely, the familial tendency towards idiosyn- 

 crasies. It has been established that these idiosyncrasies may occur very 

 definitely in families and Cook and Vandeveer have brought out the fact 



