DERMATOSES IN METABOLIC DISTURBANCES 695 



Howard Fox has shown. There is almost no group of general disturbances 

 that does not, in one way or another, involve the skin. 



The integument may be the starting point of disease, as in mycosis 

 fungoides, but more commonly it is merely a participant. All of the 

 examples cited in the previous paragraph attest to this. Before embarking 

 upon further details, however, it will be necessary to elaborate certain 

 facts, already hinted at, realization of which is fundamental to a broader 

 understanding of dermatoses. A generation ago Besnier postulated the 

 doctrine of skin reactions, a trite enough concept, perhaps, and yet com- 

 prehension is intimately involved in reiteration of the obvious. It must 

 be grasped that abnormal tissue responses present a restricted range of 

 possibilities. Thus a certain clinical picture, definite enough objectively, 

 may have many causes; thus urticaria may be due to scores of foods, 

 to syphilis, to the nettle, or to the jellyfish (actinozpa). The mechanism 

 may be prevailingly anaphylactic, but the agents are legion. Conversely, a 

 single agent may evoke several pictures, subject to biochemical factors we 

 cannot yet envisage. The bromids serve as an example. They may 

 provoke erythemas, vesicles, pustules, or granulomas. If so many factors 

 may produce a single objective phenomenon like urticaria ; or one factor, 

 as the bromids, may produce so varied a series of phenomena, it is easy 

 to grasp that concepts in clinical dermatology are subject to enormous 

 excursions into the field of error, largely subjective, but what is worse, 

 more largely indeed objective. 



With the difficulties, then, of the theme in mind, let us try to define 

 the subject of this thesis. Eliminating anomalies, infections, and neo- 

 plasms, those dermatoses will be dealt with which are prevailingly in- 

 flammatory, and the etiology of which is obscure. What is known of their 

 causation depends upon circumstantial evidence which supports the belief 

 that they are related to or depend upon general disturbances. It is the 

 object of this exposition to mention what littl is known, and whatever 

 additional may be surmised. 



Dermatoses Conceived to be Due to or Associated with 

 Digestive Disturbances 



Dermatoses have been associated with digestive disturbances as in- 

 determinate as mere constipation, or as concrete as fat or starch indiges- 

 tion. Johnston ascribed the seborrheas, and particularly acne, to starch 

 indigestion. Towle and Talbot considered infantile eczema due to either 

 fat or carbohydrate indigestion; in a grosser form solid, undigested 

 food particles were demonstrable in the stools. The former was 

 more exudative in character ; the latter more chronic. Czerny, years ago, 

 ascribed infantile eczema to the "exudative diathesis," a condition oc- 



