284 THE INTERNAL SECRETIONS 1920 



angioneurotic edema, could not possibly continue as 

 they do without the action of some such adjuvant; and 

 that the source of this adjuvant is the adrenal glands 

 seems most logical. Whether its effect is exerted 

 through the blood stream, in the form of adrenin, as we 

 know it, or is brought about through some as yet not 

 fully-understood action of the gland upon the nervous 

 system, cannot be said with any degree of certainty; 

 yet, whatever be the means of transmission, the pre- 

 ponderance of circumstantial evidence points to the 

 adrenal medulla as the source of the impulse which 

 causes the persistence of long-lived urticaria-like le- 

 sions. In other words, hyperadrenia most probably is 

 the cause of the persistence of angioneurotic edematous 

 lesions. 



What then is the cause of the lesions themselves? 

 As has been pointed out, we know that ordinary urti- 

 caria is preceded by the introduction into the system 

 and the blood stream of foreign protein of whatever 

 kind, and that angioneurotic edema usually is preceded 

 by fright or other nervous shock, by sudden imposition 

 of responsibility or other worry, or by exertion to the 

 point of fatigue. In the first case probably only the 

 foreign protein is a factor. Yet, since urticarias do 

 not develop except where elimination is suddenly de- 

 creased, the normal alkali reserve of the body lowered, 

 and acidosis of degree exists, the addition of a foreign 

 protein represents an increased wear and tear upon all 

 parts of the system, and thus places added demands 

 upon the detoxicating apparatus of which the thyroid 

 gland is a prominent factor. To terminal vessel walls 

 already irritated by increased blood-borne wastes comes 

 added irritation in the form of a new foreign protein. 

 To them likewise come added vasodilating impulses 

 from increased thyroid functioning. Here and there 

 in terminal vessel walls fatigue of vasodilators super- 

 venes, often precipitated by external irritation, such as 



