50 CLINICAL DIAGNOSTICS. 



2. Papules {papulae) are small cutaneous elevations of solid 

 consistency varying in size from that of a pin head to that of a 

 small pea. 



3. Vesicles (vcsiculae) are elevations of the outer epidermal 

 layer due to the accumulation of fluid beneath. They vary from 

 the size of a millet-seed to that of a pea. 



4. Blisters {bullae) are large vesicles. 



5. Pustules {pustulae) are vesicles containing pus, and are 

 therefore colored yellow. 



6. Ulcers {iilccra) are suppurating wound surfaces which re- 

 sult from necrosis of tissue. 



7. Scales {squamae) are epidermic lamellae which have be- 

 come detached from the skin's surface. 



8. Scabs, or crusts, are dried masses of exudate upon the sur- 

 face of the integument. 



9. Hives (urticaria, n-ettle rash) are due to swellings of "the 

 papillary bodies, producing well-defined evanescent rounded ele- 

 vations, resembling welts raised by a whip. 



I. X o n - p a r a s i t i c Skin D 



s e a s e s . 



1. Alopecia (baldness) is a loss of hair due to some disturb- 

 ance in the skin's nutrition. It may not be attended by lesion. 



2. Blood sweating {heinatidrosis) is the spontaneous appear- 

 ance of blood upon the apparently intact surface of the integument. 

 It is peculiar to Hungarian horses. 



3. Prurigo is a papular eruption accompanied by intense itch- 

 ing. Biting and rubbing induce additional lesions. 



4. Summer surfeit {acne simplex) is a nodular eruption occur- 

 ring usually over the neck and shoulders, leading to a loss of hair. 

 [It is seen mostly during the hot months. This condition is often 

 erroneously attributed to some "disorder of the blood." Its chief 

 cause is neglect of proper grooming and care of the skin of horses.] 



5. Fagopyricm is an acute, diffuse, itchy inflammation of the 

 non-pigmented skin of the head, due to grazing on growing buck- 

 wheat in bright sunshine. Brain symptoms sometimes compli- 

 cate the disease. 



6. Eczema. In a general way the term eczema designates an 

 exudative dermatitis. It has much in common with the catarrhs 

 of mucous membranes, and like the latter can pass through the 

 varied stages of erythema with desquamation, papule, vesicle and 

 pustule formation and finally squammae. It is very common in 

 >dogs, appearing along the back. 



