128 ECZEMA. 



merely represent the different forms of the disease in various situations 

 and subjected to dissimilar influences. 



Eczema may be acute or chronic ; the latter form is far more frequent 

 and may attack every portion of the body, while the former may be con- 

 fined to certain locations. A1J forms of the disease are accompanied with 

 intolerable itching. 



Causation. —Eczemas are in part primary diseases and in part sympto- 

 matic. The primary result from immediate irritation of the skin, as 

 caused by acrid medicated applications in ointments, etc., by extremes of 

 temperature, and by mechanical injuries affecting the skin directly. Cro- 

 ton oil, strong mercurial ointments, alkaline soaps, iodine, etc., when 

 applied are frequent causes of eczema. Mechapical causes are illustrated 

 by the irritation of the skin produced by the nails in scratching; eczema 

 accompanying parasitic diseases is generated in this way. Prolonged, 

 very hot baths are sufficient in some cases to induce the disease under 

 consideration. 



The symptomatic causes are not so apparent; we know that attacks of 

 eczema occur in consequence of certain internal diseases, but their anal- 

 ogy has never been positively determined. Among the symptomatic 

 causes are indigestion, injudicious feeding, want of exercise, and impov- 

 erished blood. 



Eczema frequently appears as a sequel to long exhaustive illnesses, and 

 is very often associated with liver derangements. In highly nervous tem- 

 peraments there seems to exist a predisposition to eczema, and " in- 

 breeding " has been condemned as a possible cause. That the disease is 

 hereditary as asserted by some has never been clearly proven. That want 

 of cleanliness might possibly induce the affection can be readily appreci- 

 ated. An excess of animal food is another cause assigned, but further 

 proof is necessary before this can be accepted as indisputable. The feeding 

 of starchy food in excess induces disturbances of the nutritive functions, 

 and eczema frequently results. 



Worms by intestinal irritation and other influences on the system might 

 give rise to the affection. Puppies during the period of dentition some- 

 times suffer eczematous attacks. Many other causes have been assigned, 

 and many cases occur, the origin of which it is impossible to explain. 



Eczema is not contagious, but in certain stages when the secretion is 

 profuse, the disease can be communicated by actual contact of a sufficient 

 duration. To be more explicit a healthy dog might be allowed to play 

 with one affected with eczema, and be many times in momentary contact 

 without acquiring the disease ; but were they allowed to occupy the same 

 sleeping-box, and the healthy skin of one remain sufficiently long in con- 

 tact, with the diseased skin of the other, from which there exuded a profuse 



