Ringworm of the Scalp (Tinea tonsurans) usually occurs in children, and is especially prevalent when the nutrition is defective, or there is a scrofulous taint in the constitution. In infants, and after the age of puberty, it is rare, and can usually be readily cured. It appears in the form of round, scaly, irritable patches on different parts of the head; and the irritation often occasions the formation of minute vesicles. The hairs at these spots become dry and twisted, and are easily removed, but when the disease advances they break close to the scalp if an attempt is made to extract them. The stumps, and the epidermis surrounding them, become covered with a characteristic grayish-white powder, consisting of the sporules of the fungus. The diseased parts are slightly elevated and puffy, and differ from the healthy scalp in colour, being bluish or slate-coloured in dark persons, and grayish red or yellow in fair patients. The inflammation will last as long as the growth of the fungi continues; and even when they die spontaneously, as sometimes occurs, the affected spots may become bald in consequence of the hair-bulbs having become atrophied. This condition, however, generally passes off in time. In some children only single hairs here and there may become or remain affected, and such cases are particularly apt to lead to the spread of the disease, because they are difficult to detect, and often escape recognition.
Ringworm is also sometimes met with in the beard, giving rise to one form of the troublesome disease known as Sycosis. Ringworm is extremely contagious; and when a case of it occurs in a family or a school strict precautions are necessary to prevent its spreading to others. The greatest care should be taken that no brushes, sponges, towels, caps, &c. touched by the patient are used by others. The hair should be kept short, and the scalp anointed daily with carbolic oil, 1 in 20; a cap of linen or oilsilk should be worn night and day; and whatever remedy is selected should be steady and perseveringly applied. No child with ringworm should be allowed to go to school, unless under very special precautions, nor to the latter or hairdresser; and intercourse with other children should be permitted as little as possible except in the open air.
Treatment.—Ringworm of the body is usually not difficult to cure. The application of some parasiticide, white precipitate ointment, solution of sulphurous acid, tincture of iodine, usually quickly kills the parasite and so ends the disease. Ringworm of the scalp, on the other hand, is often an extremely intractable affection, because the parasite extends deep into the hair-follicles, and it is very difficult to bring the remedies employed satisfactorily in contact with it in this situation. In recent cases the remedies recommended above are often effectual; but those which have become chronic sometimes tax the ingenuity of the physician and the patience of the nurse to the utmost, and may even last till advancing years make the soil unfavourable for the further growth of the parasite.
Ringworm in the lower animals, as in the human subject, consists of the growth of a vegetable fungus on the surface of the skin, is common amongst young animals, is decidedly contagious, and communicable from man to the lower animals, and probably, also, from the lower animals to man. Commencing with a small itchy spot, usually about the head or neck, or root of the tail, it soon spreads, producing numbers of scurfy circular bald patches. It is unaccompanied by fever, and seldom interferes seriously with health. After washing with soap and water, run over the spots lightly every day with a pencil of nitrate of silver, or rub in a little of the red ointment of mercury, or some iodide of sulphur liniment. See works by A. Smith (3d ed. 1885) and G. Thin (1887).