The skin of the affected areas has a smooth, whitish, polished, atrophied appearance, and is usually entirely devoid of hair or with a few straggling long or short hairs scattered over it. The orifices of the follicles become less appreciable, and the skin is thin, and resembles that seen in the baldness of advanced years. The hairs surrounding the affected area are usually found to be firmly seated in their follicles, but if the patch has not ceased enlarging they may be loose and readily extracted. In some cases about the border are noted a few short atrophied hairs, resembling the short, broken-off hairs of tinea tonsurans. At first the skin may be slightly puffed, but usually it is on a level with the surrounding parts; later, it may be somewhat depressed, as though atrophied. It is neither scaly nor inflamed. Slight anæsthesia may be present. There are, as a rule, no subjective symptoms. Involving the regions of the moustache and eyebrows, the clinical phenomena are essentially the same as when affecting the scalp. In those cases in which universal loss of hair results, the process usually begins in the same way, first appearing as well-marked areas, which rapidly increase in size; new patches are added, coalescence results, and eventually the entire surface is involved. After the disease has come to a standstill it may so remain indefinitely, or lanugo hairs may appear from time to time, reach an inch or a fraction thereof in length, may become slightly darkened, and then fall out. Finally, in favorable cases, instead of falling out, their growth continues; they become dark, and recovery takes place. In these latter cases the disease may have existed several months before signs of a permanent regrowth show themselves; on the other hand, several years may have elapsed.

The disease is met with in both sexes, in children and adults, and among the wealthy and the poor. It is not a rare disease, nor is it common. Impaired nutrition as the result of functional nerve-disturbance is probably the important etiological factor, leading to the view that the affection is a trophoneurosis. It is often seen to follow neuralgias, nervous shock, and debility. Morphoea and vitiligo, both diseases of a neurotic character, are occasionally seen in association with it. In the greater number of cases no appreciable cause is discoverable. It is not parasitic, nor is it contagious. Microscopic examinations have given negative results, the skin remaining normal and the glandular structures unchanged. Atrophy of the hair shafts and bulbs, and occasionally breaking and bulging of the hairs, are usually noted. The atrophic condition of the bulbs is similar to that seen in hairs which have reached the end of their normal life.

The disease with which alopecia areata may, by the inexperienced, be sometimes confounded is tinea tonsurans, and yet the incomplete baldness, the short, stumpy, split, gnawed-off-looking hairs, the scaliness, the increased prominence of the follicular openings, and the history and course which characterize ringworm, are entirely different from the clinical signs of alopecia areata. Where there is doubt the microscope is to be employed. It is to be remembered, also, that ringworm of the scalp is not seen in individuals past the age of puberty. The peculiar clinical features of the disease will distinguish it from other forms of baldness.

TREATMENT.—The uncertainty of the duration and ultimate termination of the disease is to be kept in view in expressing an opinion. It may be stated, with a degree of positiveness, however, that in young individuals the eventual result is, as a rule, good; but occurring in persons past adult age, the prognosis as to a regrowth is not so favorable, and becomes less so as age increases. The length of time elapsing in favorable cases before the hair reappears, as already mentioned, is uncertain: it may be several months, or on the other hand, as many years. On both points proper and persevering treatment has sometimes a material influence.

Local and general measures are called for. Of the two, the general treatment is the more important, and among remedies employed arsenic stands prominent. It should be continued for months. In addition, such tonics as iron, quinine, cod-liver oil are to be advised as the case demands. In some instances potassium iodide in moderate doses is of service.

External treatment is of value, and is in most cases to be advised. The object in view is a stimulation of the vascular supply, and through this an improvement in the nutrition of the papillæ and hairs. The same remedies in various combinations are employed as in the treatment of other forms of alopecia. Rubefacients and irritants, such as alcohol, the essential oils, sulphur, tar, cantharides, corrosive sublimate and other salts of mercury, carbolic acid, iodine, turpentine, ammonia, chrysarobin, and spiritus saponatus kalinus, are variously used. They are, as a rule, employed either in alcoholic or ethereal fluids or in the form of oils or ointments. It is to be borne in mind that the scalp tolerates strong remedies. The applications are to be made once or twice daily, according to the demands of the case, and with considerable friction, employing for the application a flannel rag or mop. Such remedies as iodine, corrosive sublimate, are usually to be painted or dabbed on.

Sulphur, two to four drachms to the ounce; corrosive sublimate, one to four grains to the ounce of alcohol; tar, ol. cadini, or ol. rusci, one to four drachms to the ounce of alcohol or ointment,—are all serviceable remedies. Cantharides and capsicum are stimulating, and may be prescribed as in the following formula:

Rx.Tinct. cantharidis,
Tinct. capsici, aa.		fluidounce iss;
Olei ricini,fluidrachm ij;
Alcoholis,fluidrachm vj;
Spts. rosmarini,fluidrachm ij. M.

The following, containing the oil of mace, is also serviceable: