ACTIVITIES OF THE SKIN 259 



pies. Hot drinks and muscular effort assist diaphoresis. Nervous 

 excitement, as fear, pain, nausea, produces the same effect. The 

 toxins of certain diseases also cause excessive perspiration, as in 

 the nocturnal sweating of tuberculosis, the crisis of pneumonia, 

 and other instances. 



In fevers, cutaneous vessels are dilated, but the nerve stimulus 

 to cell action is dulled and the skin remains dry. 



Some other diseases have a similar effect; loss of water by 

 colliquative diarrhea (characterized by profuse liquid stools) leaves 

 the skin dry. In diabetes mellitus a very troublesome symptom 

 is dryness of the skin with pruritus or itching (and a tendency of 

 the connective tissue to break down in boils). 



The effect of baths upon the skin is to abstract heat, improve 

 the tone of cutaneous structures, and favor the action of the glands. 



In renal diseases, activity of the skin is to be promoted; in fevers, 

 activity of the kidneys, as well as of the skin. 



The skin has a slight degree of absorbent action in the areas 

 where it is thinnest; this power is utilized for inunctions. 



Clinical note. The skin should be well rubbed until it is warm and quite 

 dry of perspiration or oil before applying a medicine by inunction, in order 

 that the circulation of cutaneous vessels may favor absorption. Animal oils 

 are more easily absorbed by the skin than vegetable oils. 



SUMMARY 



The skin is protective, excretory, an organ of special sense, of heat 

 regulation and to a moderate extent of absorption. 



