148 INFECTIOUS AND PARASITIC DISEASES. 



Or Sarcoptes hominis, the itch-mite, is 

 AcARus another parasitic insect which forms bur- 

 ScABiEi rows in the skin. Only the female pro- 

 (itch-mite). duces lesions, the purpose being the depo- 

 sition of her eggs. The portions of the 

 body selected are those where the skin is thinnest, viz., 

 in the webs between the fingers, at the bend of the elbows, 

 in the axilla, upon the penis, at the bend of the knees, 

 and about the ankles. In children, burrows may be 

 found over the whole body. 



Where the mite penetrates the skin a little vesicle is 

 formed, and the direction of the burrow is indicated 

 by a rough, dark line. However, because intense 

 itching always accompanies the insect's activity, the 

 only lesions discoverable may be scratch-marks. Itch- 

 ing is most complained of at night, the period when the 

 female is active. The itch-mite is so small that it is 

 seldom seen and the diagnosis of its presence is made 

 entirely from the character and situation of the lesions. 

 It is of historical interest that the first Napoleon was a 

 sufferer from ''itch" for ten or twelve years until cured 

 by the physician Couvisart. 



The parasite is contracted by intimate contact with 

 a person who harbors it. 



Eradication of the mite is easily accomplished by 

 scrubbing the lesions with soap and a soft brush, 

 followed by rubbing Balsam Peru well into the bur- 



