INFLAMMATORY CONDITIONS OF THE SKIN. 385 



becomes ruptured, and the fluid dries up in a yellow, gray, or 

 brown crust, under which the regeneration of the lost epidermic 

 layer goes on rapidly. 



Now and then the inflammatory process shows it is in the neigh- 

 borhood of a follicle and its sebaceous glands, and we have the 

 formation of a dark -red, very sensitive nodule, and finally suppu- 

 ration of the same membrane and its adjacent tissues. As a con- 

 sequence of that we find that the glands and canal of exit are 

 filled with purulent or bloody matter. Soon the internal follicles 

 become involved; the masses of matter can be easily pressed out 

 of the orifice of the follicle, and we may have an elasticity of the 

 purulent cavity surrounded by infiltrated cutis in which we find 

 the hair has become entirely detached from the follicle and falls 

 out. This condition is generally a rather serious affection in the 

 dog, as in this animal there are always several follicles which are 

 accumulated into one group with a common orifice, and in every 

 case of cutaneous disease we find a group of affected sebaceous 

 glands. 



In very bad cases peri-glandular and peri-foUicular inflamma- 

 tion may become so acute that we see the formation of an extended, 

 nodule-shaped, dark-red swelling, forming a so-called "boil." 

 This is marked after a certain period by a yellowish-green, necrotic 

 thrombus, which becomes detached by purulent disintegration of 

 the surrounding tissue, and is sloughed after the pus has been dis- 

 charged. In such cases we find that not only is the external sur- 

 face of the skin impaired, but the corium is aifected, and as the 

 follicles are destroyed the hair does not return. The formation of 

 abscesses and ulcerations, also infiammations of the skin, will be 

 discussed further on. 



In chronic cutaneous inflammation we may see the formation of 

 hypertrophic as well as atrophic conditions. In the former case 

 we find as a consequence of the constant increase and congestion 

 of blood to the part the formation of superfluous connective tis- 

 sue, whereby the skin may be thickened several times its normal 

 size, and may form large folds or callosities, and in rare cases 

 club-shaped or warty elevations; in the latter case the corium 

 becomes thinner. This is also the case with the epidermis. Its 

 tissue is either greatly reduced or greatly increased in size, and in 

 the latter case the epidermic cells which proceed from the deep 



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