I DISEASES OF THE SKIN 287* 



What changes may tahe place in the skin in erythema f 



Tlie bloodvessels dilate, tlie papillary layer swells more or 

 less, there is serous infiltration of the tissues (inflammatory 

 edema). In cases -where the hyperemia of the skin persists 

 for some time, desquamation of the epithelium follows.. 

 Should the serous inflammation accumulate in the rete 

 mucosum, blisters are formed as the infiltrated serum raises 

 the epidermis from its basis. 



in what animals is erythem,a seen ? 



In all animals, but is best observed in those which have a 

 non-pigmented skin. In the horse, seats of predilection are 

 those parts exposed to harness friction and in the flexion sur- 

 face of the fetlock. 



Which are the clinical symptoms of erythema ? 



Very slight swelling, pain and arterial redness of the skin; 

 later the hair may drop out and the epidermis scales off. 

 When in the flexion surface of the pasterns, the pain may be 

 sufficient to produce lameness (erythema of the flexion surface 

 of the fetlock represents the mildest form of what is vulgarly 

 termed "scratches"). 



Outline the treatment of erythema ? 



Remove the irritant; mild astringents are indicated. 

 What is suppurative dermatitis f 



A suppurative inflammation of the skin due to an infec- 

 tion with pus-producing bacteria. 

 How does suppurative dermatitis occur f 



Either diffused and superficial, when it is termed puru- 

 lent dermatitis, or circumscribed, when it is known as derma- 

 titis pustulosa; or in those cases where the suppurative pro- 

 cess is confined to the hair follicle and its immediate neigh- 



