352 EDEMA 



fibers may cause edema. It is furthermore possible that nervous 

 stimulation may lead to excessive metabolic activity, with an ac- 

 cumulation of crystalloidal products and acids sufficient to cause 

 edema when supplemented by active congestion and some resulting 

 pressure upon the lymph-vessels. There are certainly many instances 

 in which edema seems to depend upon nervous disturbance; for ex- 

 ample, edema in the area of distribution of a neuralgic nerve; sudden 

 joint effusions in tabetic arthropathy; and especially the typical 

 "angioneurotic" edema. ^^ The only explanation that seems open is 

 the one given above, namely, a combination of local h^-peremia and in- 

 creased metabolic activity. Even the urticarias of apparently me- 

 chanical origin (urticaria factitia), show evidence of a toxic action, 

 in that there occurs a severe nuclear fragmentation (Gilchrist).^" 



Hereditary Edema. — In a number of families there has been ob- 

 served a peculiar inherited tendency to the occurrence of acute attacks 

 of local edema, which not infrequently have proved fatal when in- 

 volving the glottis. ^^ There can be little question that these instances 

 of hereditary edema depend upon a nervous affection of some kind, it 

 being practically an angioneurotic edema; but how the edema is pro- 

 duced, and what the nature of the nervous alteration may be, are as 

 mysterious as are most other so-called "nervous inheritances." There 

 also are cases of congenital edema, which may occur repeatedly in 

 the fetuses of the same mother and cause habitual miscarriage;^^ and 

 still another class of cases in which the children are born apparently 

 healthy, but develop fatal dropsy w^hen a few weeks old.^'' Nothing 

 is known as to the cause of this condition. Patein*^ has analyzed the 

 fluid in a case of congenital ascites and found it somewhat more like 

 an exudate than a transudate. 



Nutritional Edema ("War Dropsy" or Famine Edema). ^(Discussed 

 under Deficiency Diseases, Chapter xii.) 



COMPOSITION OF EDEMATOUS FLUIDS^^ 



As is well known, the composition of edematous fluids varies greatly 

 according to the cause of the edema and the place where it occui's. 

 In general, non-inflammatory edemas (transudates) contain much less 

 protein than do the inflammatory exudates, as is shown by the follow- 

 ing taljle of analyses by Halliburton^'* and by Rornheim's-'" deter- 

 minations of proteins in ascitic fluids. 



'"' Metabolism in angioneurotic edema is discussed bv ISIilliMand Pepper, Arch. 

 Int. Med., 191G (18), 551. 



'-"Johns Hopkins Hosp. Bull., 1908 (19), 49. 



"Literature, see Fairbanks, Amer. Jour. Med. Sci., 1904 (127), 877; Hope 

 and French, Quart. Jour. Med., 1908 (1), 312; Crowder, Arch. Int. Med., 1917 (20), 

 840. 



" W. Fischer, Berl. klin. Woch., 1912 (49), 2403. 



"Edgeworth, Lancet, 1911 (181), 211). 



"Jour. IMiariu. et Cliim., 1910 (102), 209. 



" Many data are given by Cierliarlz, ilamlbuoh dor Bioi'heniio, 190S, II (2), 137. 



'-0 Adaiiii, Allbutt's System, 189(5 (1), 97. 



" (Quoted by llamnuirsten, "Physiological C'homistrj-." 



