This section is from the book "The Home Hand-Book of Domestic Hygiene and Rational Medicine. Volume 2.", by J. H. Kellogg, M.D.. Also available from Amazon: The Home Hand-Book of Domestic Hygiene and Rational Medicine, Volume 2.
This is a parasitic disease, in which a fungus grows upon the skin. The scalp, the beard, the nails, or the general surface of the body may be affected. In Fig. 344 may be seen the appearance of the fungus under the microscope. Fig. 345 shows an affected hair greatly magnified. The fungus is called, scientifically, tricophyton tonsurans. It is a contagious affection.
Fig. 344.-Ringworm Parasite, greatly magnified.
Fig. 345. A Hair affected by Ringworm.
When it occurs on the body, the disease usually spreads in a circle, from which the affection takes its name.
When the scalp is affected, the hair falls in circular spots, upon examination of which numerous short stumps of hairs may be seen, in which respect this disease differs from baldness due to other causes. The affected portions of the scalp present the appearance of the skin of a plucked fowl, and numerous white scales. The disease extends into the hair follicles and the hairs. The affection is quite obstinate, and when it exists for a long time, may occasion permanent baldness. It occurs most often in charitable institutions, where a large number of children are brought together.
Ringworm of the beard, or sycosis, commonly known as "barber's itch," is a not uncommon malady, but often very obstinate to cure. It rarely occurs except in persons accustomed to bo shaved at a barber shop, where the disease is almost always contracted. Not infrequently a very considerable degree of inflammation of the skin of the face is produced, giving rise to nodules, pustules, and various other forms of eruption.
The fingernails are sometimes affected by this disease, as well as other parts, becoming dry, thickened, brittle, and opaque.