SCABIES (THE ITCH).—A skin disease caused by the itch-mite, a small insect which may enter the• skin and cause extensive irritation and scratching. The mite principally burrows into the skin at the wrist, the folds between the fingers, the inner surface of the elbow, the armpit, the navel, the buttocks, the inner border of the foot, and in all parts which are compressed by tight garments (such as corsets, suspenders, waistbands, etc.). It also attacks the external genitals in men, and the region of the nipple in women. On close observation the infected area discloses Nvhitish lines, several milli metres long. These are the burrows of the mites (see Fig. 366), and each one ends in a yellowish-white pimple. From this elevation in the skin it may be possible, with the point of a penknife, to remove the itch-mite, a moving speck which can he crushed between two finger-nails. As a result of the burrowing and the consequent itching and scratching, also other parts of the body may show red or scratched pimples and blisters, covered with crusts.
Scabies does not heal spontaneously ; it should be treated by a physician.
Kerosene, which is useful in exterminating other kinds of parasites, is not effective in this case, but may eventually he harmful. It is not neces sary to disinfect beds, mattresses, and linen, as the mite cannot live in them. But all persons who live in close proximity to the affected indi vidual, or who have been sleeping in the same bed, must be carefully examined.
The itch was formerly believed to he due to a bad condition of the blood, and it was thought that the disease might he " driven inward." These and similar opinions, which are still found disseminated among certain classes of people, and mentioned in quack literature, are erroneous. The eruption is caused by the irritation produced by the mites, and by the consequent scratching ; and a disease which is due to the presence of a parasitic organ ism in the skin cannot be " driven in." The itching and the eruption dis appear as soon as the mites are destroyed by external remedies. Special treatment is required only in exceptional cases.