705 



subvariety so closely simulates dermatitis herpetiformis that it is sup- 

 posed to be the result of disturbed nitrogen metabolism. 



Furunculosis. Save for the factors incidental to puberty, the etiology 

 of furunculosis is similar to that of acne. In addition, the disease is 

 often caused by diabetes. 



Gangrenes. Many of the views applied "to acroasphyxia equally apply 

 to the gangrenes. Diabetes, syringomyelia, tabes, atherosclerosis, etc., to 

 say nothing of the so-called spontaneous gangrenes of the skin, those due 

 to self-mutilation (hysterical or insane subjects), gangrenous zoster, and 

 varieties due to asthenia, as decubitus, indicate the tremendous range of 

 causative possibilities in this condition. Biochemical, central nervous, 

 vascular and trophic diseases are among the organic causes, while mental 

 diseases are among the functional. 



Pemphigus. This disease in its different forms has been subjected 

 to about the same series of explanations as eczema and dermatitis her- 

 petiformis. The disease is invariably fatal, however, and behaves much 

 more like an infectious syndrome than anything else. 



Prurigo. This disease is regarded by many as papular urticaria, in 

 which event its etiology is that of the latter disease. (See below.) By 

 others it is regarded as a metabolic disease provoked in a manner similar 

 to dermatitis herpetiformis. 



Prurigo lymphatica is a nodular disease of the skin found in lymphatic 

 leucemia. 



Psoriasis. The greater part of the section on diseases due to disturbed 

 nitrogen metabolism is devoted to psoriasis. There is no object in re- 

 writing the passage. 



Rosacea. This disease is caused by chronic gastritis, and conditions 

 producing the latter, such as alcoholism, hyperacidity, gastric ulcer, ex- 

 cessive use of condiments, overindulgence in carbohydrates, and in short 

 all chronic alimentary disturbances. Gynecological diseases, including the 

 disturbances of the menopause, may also be responsible. Everything stated 

 of ordinary acne, except what relates to puberty, applies to rosacea. 



Seborrhea. Unless seborrhea is due to an undiscovered infection, the 

 paragraphs on acne and rosacea are applicable. 



Urticaria. This condition, in part, is explicable in the same manner 

 as multiform erythema. A great number of cases are due, however, to 

 food sensitization, or sensitization to other alien proteids. Chronic forms, 

 particularly those resembling prurigo, may be due to disturbed nitrogen 

 metabolism. Thus the factors may be diet, anaphylaxis, biochemical de- 

 rangements, and finally, still unsuspected causes. Contributory factors are 

 food, organic or functional maladies of the alimentary tract, and parenteral 

 exposure to proteids to which the patient is susceptible. 



Xanthoma. Xanthoma diabeticorum is due to diabetes, xanthoma 

 tuberosum to disturbed fat metabolism. 



