The only harm done by freckles is to your vanity. They and sunburn both, in fact, are protective actions on nature's part, filling the skin with coloring matter, or pigment, so as to protect it, and the tissues below, from the irritating effects of the strong rays of light.
A like deposit of pigment, in greater amounts, in the skins of races who live in or near the tropics, gives rise to the characteristic coloring of the black, brown, and yellow races. The pigment, or coloring matter, is of exactly the same kind in all, from the negro to the white. The brown race having a little less of it than the negro, the yellow race a little less yet, and the white least of all, though there is some of it in even the whitest of skins.
Real Skin Diseases. Most of the serious and lasting diseases of the skin are caused by the attack of germs. Perfect cleanliness and ventilation are the best protection against them all; but if you should be unfortunate enough to catch one of these diseases, your doctor will be able to give you the mild germicide or antiseptic that will kill the particular germ that may have lodged upon your skin.
The commonest form of inflammation of the skin is called eczema, and eight-tenths of all eczemas are due to some mild germ, and can be cured by the appropriate poison for it.
Other diseases, particularly of the scalp, such as ringworm and dandruff, are due to other forms of vegetable germs, and may be cured by their proper poisons; while others, such as the so-called "prairie itch" (scabies), and lice in the hair, are due to the presence of tiny animal parasites.
The Hookworm. Another disease which enters through the skin is the now famous hookworm, or blood-sucking parasite, which has been found to be so common in tropical regions and in our Southern States. This parasite has the curious habit of attaching itself by hooks surrounding its mouth (which gave it its name), to the lining of the human intestine, particularly its upper third. There it swings, and lives by sucking the blood of its victim. When the worm has once attached itself in the intestine, it may live for from five to fifteen years. All this time it is constantly laying eggs; and these eggs, which are so tiny that they have to be put under a microscope to be seen, pass out in the feces; and if they are not deposited in a proper water closet, or deep vault, but scattered about upon the surface of the soil, the eggs quickly hatch into tiny, little wriggling worms called larvæ, which are still scarcely large enough to be seen with the naked eye.
These larvæ live in the soil; and, when it is wet and muddy, they get up between the toes of boys and girls who are going barefoot, burrow their way in through the skin, and produce a severe itching inflammation of the skin of the feet, known as "ground-itch," "toe-itch" or "dew-itch." When they have worked their way through the skin, they bore on into a blood vessel, are carried to the heart, pumped by the heart into the lungs, and there again work their way out of the blood vessels into the bronchial, or air tubes, crawl up these through the windpipe and voice organ into the throat, are swallowed into the stomach, and from there pass on into the upper intestine to attach themselves for their blood-sucking life. If they are sufficiently numerous, their victim becomes thin, weak, and bloodless, with pale, puffy skin, and shortness of breath; he is easily tired on the least exertion, and ready to fall a victim to any disease, like tuberculosis, pneumonia, or typhoid, that may happen to attack him.
Their spread can be absolutely prevented either by the strict use of toilets or deep vaults, thus preventing the deposit of feces anywhere upon the surface of the ground; or by the constant wearing of shoes or sandals, thus preventing the larvæ from attacking the feet and working their way through the skin and body into the intestine.
Fortunately, the disease is as curable as it is common, and two doses of a proper germicide, with a day in bed, and a laxative, will promptly cure it except in the worst cases.
The Rashes of Measles, Scarlet Fever, etc. Many of the infectious fevers, such as measles, scarlet fever, chicken-pox, and smallpox, are attended by rashes, or eruptions, upon the surface of the skin, due to a special gathering or accumulation of the particular germs causing each disease, just under the skin. When the skin sheds, or flakes off, after the illness, the germs are shed in the scales and float, or are carried about, and thus spread the disease to others.