The eruption appears much more frequently on the scalp than elsewhere; but it occasionally appears also on other parts of the body, as the face, neck, limbs, etc, to which it is probably generally transferred either from the head by the nails of the patient, or from contact with some other person.

The disease shows itself first in the form of specks, of a yellow colour, like minute crusts, scarcely rising above the surface, and appearing as if set in the skin. There is usually little redness about them. They are scattered irregularly, without any particular arrangement, frequently permanently distinct, but sometimes so crowded as to cover portions of the surface completely. They are generally seated at the roots of the hairs, one of which passes through the centre of the crust. The eruption is attended with more or less itching. When the crusts are numerous, they often meet at the outer edges, so as to form a continuous incrustation of greater or less extent. Sometimes the whole scalp is covered, as by a closely fitting cap. If permitted to remain undisturbed, the crusts continue to adhere for months or years, but undergo a kind of disintegration on the surface, exchanging their yellow for a whitish colour, becoming brittle, and breaking into small powdery fragments. The hair upon the diseased surface, in this advanced stage, generally falls; and, either none appears afterwards, or that which is produced is of an altered character, being downy and destitute of colour.

When want of cleanliness exists along with the disease, insects are often generated beneath the crusts, intense itching is excited, and the patient is unable to resist a propensity to scratch the parts, sometimes even violently, thus tearing off the scabs, causing bleeding and excoriated spots, and adding greatly to the inflammation. In this state of the scalp there is usually an extremely fetid odour. With proper cleanliness, and upon the removal of the scabs, the odour is less disagreeable, but still nauseous.

The disease, when long established, is thought to retard the development of the system, and to have a debilitating effect upon the intellectual faculties. A tendency to scrofulous disease is also occasionally shewn, and its development is favoured by the eruptive affection. The nails, in old cases, are said to be sometimes thickened, elongated and roughened, and to become of a yellow colour.

The duration of the complaint, if left to itself, is uncertain. It may continue for many years a source of much distress to the patient and of disgust to those about him; but it is seldom, if ever, directly fatal. When it ends favourably, under proper treatment, new crusts are no longer formed upon the removal of the old ones; pustules cease to show themselves, and the skin, though it may have been apparently disorganized, returns gradually to a healthy condition, with only some redness left, which ultimately disappears. The hair, however, is sometimes never reproduced, and when it does come forth, has usually for a long time an unnatural appearance. Still this is frequently restored in time, especially ' when an early cure has been effected.

The general health of the patient should be attended to, and if there should be any evidence of a scrofulous taint in the system, the remedies recommended in treating of that disease should be administered.. But no remedy that is not directly applied to the part can have any influence in curing the disease.

Treatment

The hair should be first removed from the part affected by cutting it close with a pair of sharp scissors. The scabs must then be removed by means of poultices of linseed meal, boiled and mashed carrots, or bread, (they should be applied warm, and changed as often as they get at all cool), or by fomentations, and afterwards by frequent washing with soap and warm water. The flannel used for these purposes should not be used for any other purpose, as it would be sure to spread the infection. The scalp should generally be washed with soap and water every day or every second day, so that the applications may have a fair chance of reaching the diseased surface.

Many applications have been used for the cure of Scald Head. One of the first objects to be attained is the removal of the hair over the diseased surface. If the hair does not come away with the scabs after the poulticing, the following ointment may be applied: Carbonate of Soda, one dram; fresh lard, one ounce; this may be rubbed on the part with a bit of soft flannel for ten or fifteen minutes every day, till the hair comes away. After the hair is removed, a plaster of Tar Ointment should be applied and kept on continually. It should be removed every second day, and the old ointment carefully washed off with soap and warm water before the new plaster is applied. Should the Tar Ointment prove insufficient of itself to cure the disease, an equal quantity of Sulphur Ointment may be added to it. Lotions of Sulphuret of Potash, Chloride of Soda, and Chloride of Lime, Sulphate of Iron, Sulphate of Zinc, and Sulphate of Copper, and various other preparations have been used. A linen cap should be constantly worn to protect the head as well from the atmosphere as from the fingers of the patient.