558 



DISEASES OF THE SKIN. 



of which the hairs fall out or are agglutinated by a viscous liquid ; 

 there are sometimes vesicles. Later, the pimples become the seat 

 of an abundant epidermic desquamation and are covered with scabs; 

 these may acquire the thickness of one centimetre; they are mainly 

 formed of epidermic cells which are disposed in stratified layers, in 

 which we may recognize graded galleries. The skin becomes indu- 

 rated, parchment-like, wrinkled, fissured, creviced, and excretes a 

 serous or purulent exudate ; it is rendered bloody here and there 

 by frictions. When the disease is old and more or less generalized 

 the animals become emaciated, fall into a cachectic condition, and 

 may perish from exhaustion. 



This mange is transmissible to man, affecting especially the hands 

 and arms of persons having the care of mangy horses (Dupont, 

 Gerlach, Weigel). According to Sick, in 1791 two hundred Hus- 

 sars of the same regiment were contaminated by their horses. 



The diagnosis of sarcoptic mange is difficult at the outset; minute 

 and repeated microscopic examinations are mostly necessary in order 

 to discover the sarcoptes, and there are cases where they are not 

 found, no matter what is done. The only symptom which at this 

 period has a real diagnostic value is a very intense pruritus which 

 is much less evident in nou-parasitic pustulous eczema (summer 

 mange, pustulous rash). These intense itchings, which contrast 

 with the slightly marked alterations of the surface of the skin, led 

 to the belief entertained formerly of the existence of prurigo and 

 pruritus in the horse (see Eczema). In cases of old and neglected 

 mange we can easily detect the acari. 



The prognosis is more serious than is generally admitted. Con- 

 cerning curability, sarcoptic mange differs essentially from psoroptic 

 mange, which ordinarily heals quite rapidly ; the former, when it 

 has reached an advanced stage, is rebellious to all medication, even 

 the most energetic ; almost always, after a treatment which has 

 been prolonged for months, we observe recurrences of the disease 

 which are often taken for successive infections, but which are mani- 

 fested in cases where the possibility of repeated contagions could 

 not be invoked. 



The observations related further on will confirm the decided 

 judgment which we have just given upon the gravity of this mange. 



The treatment consists of cleansing the diseased surfaces, soften- 

 ing the scabs with carbolated or cresolated glycerin at 5 to 10 per 

 cent., clipping the hair if necessary, and applying green soap, which 



