512 DISEASES OF THE SKIN. 



ance with the habits of the acarus scabiei, a knowledge which nas 

 completely overthrown the ancient errors regarding the origin of 

 the itch. 



SYMPTOMS AND COURSE. Generally speaking, a patient is first 

 made aware of his having scabies by an intense itching, which is worse 

 when he is warm in bed, and which is by no means limited to the re- 

 gions most frequented by the acarus, namely, between the fingers, ir. 

 the bends of the joints, upon the genitals, and between the nates ; for 

 it is also very severe upon the legs, abdomen, and chest. The most 

 conspicuous objective symptoms are nodules, pustules, and vesicles in 

 variable number, occupying the regions mentioned. In very little 

 children, whose head is often kept buried in bedclothes, they are 

 sometimes, although rarely, found upon the face. These nodules, vesi- 

 cles, and pustules do not denote different kinds of itch, but rather are 

 indicative of the stage of dermatitis excited in the skin by the presence 

 of the parasite, and still more by the scratching. In children, and in 

 other persons with tender skin, the inflammation is most apt to be so 

 severe as to form pustules, and even to suppurate. These nodules, 

 vesicles, and pustules are often excoriated by the nails, and converted 

 into bloody scabs. A much more characteristic sign of the disease is 

 afforded by the burrows of the itch-mite, which, with a little care and 

 practice, are not hard to find. They consist of dotted, sinuous, or zig- 

 zag seams, which look like the scars of needle-scratches. At their be- 

 ginning that is, at the place at which the insect embedded itself 

 there is often a vesicle, more rarely a papule or pustule ; at its termi- 

 nation there is a somewhat larger blackish or whitish point, corre- 

 sponding to the actual position of the insect. The burrows are most 

 numerous between the fingers, and upon the inner surfaces of the 

 wrist and elbow-joints, and upon the penis. In order to catch the 

 acarus, a needle must be thrust into the beginning of the burrow, and 

 carefully pushed toward its end, at the same time ripping open the 

 covering. A minute white point, which, upon attentive examination, 

 will be seen to change its position slowly, and which, after this pro- 

 cedure, is generally found on the point of the needle, is the acarus. 

 Not unfrequently an egg may be seen within her, which may be 

 squeezed out of her body by gently pressing upon the fine glass 

 cover. The itch-tracks found upon the penis are always accompanied 

 by infiltration of the skin beneath them. When the insects are ex- 

 cessively numerous, instead of the discrete efflorescences, there is a 

 diffuse eczematous dermatitis, whose scabs are inhabited by legions 

 of mites. This form, which is rare with us, but which used to be of 

 frequent occurrence in Norway, is "Norwegian itch," or Borkcn- 

 kratze. 



