A system of practical medicine. By American authors. Vol. 4

by Unknown

Canities.

Canities is a term applied to grayness or blanching of the hair. Loss of pigment in the hair may be partial or general. It may occur early in life or, as is commonly the case, as the result of old age. The change in color may take place throughout the entire hair or in parts. The color varies from slight blanching to white. It is usually grayish. In rare instances the color is to a moderate degree regained in summer. Grayness of the hair in the young—canities præmatura—is exceptional; in the old—canities senilis—it is constant, individuals differing considerably, however, as to the time of life at which the change begins. After the hair has become gray it rarely recovers its coloring matter, although occasionally in the young, after the lapse of years, the hair may again become dark. In those of a dark complexion the loss of pigment occurs, as a rule, much earlier than in those whose hair is of the lighter shades. Usually considerable time is required in the complete change to gray or white, but authentic cases are on record in which the change has taken place in the course of a night or within a few days. The pathology is obscure.

Canities, as may be readily inferred, depends upon a deficient production of pigment. The causes which gives rise to this deficiency are not understood. Hereditary influence is often noticeable. Conditions which impair the general nutrition, such as chlorosis, anæmia, fevers, etc., and those that hinder the local nutrition, as seborrhoea and inflammatory diseases of the parts, may possibly have some influence. In sudden blanching of the hair fright, intense anxiety, and the like are the usual causes. Treatment, whether internal or external, has no effect in preventing the loss of pigment or in restoring it. Dyeing, however, may be practised, and the condition masked; but it is not to be recommended, as the skin of the scalp becomes discolored and the nutrition of the hair interfered with.

Alopecia.

Alopecia consists of partial or complete deficiency of hair, irrespective of cause. There are several varieties, named according to the causes which have produced the affection. Thus, congenital alopecia consists of a partial or complete absence of hair, either over the entire surface or confined to a portion. In some instances there is scantiness or irregular development. In rare cases there is complete absence of the hair, microscopical examination failing to show the existence of hair-bulbs. In cases of congenital deficiency there usually exists an hereditary predisposition.

Senile alopecia and senile calvities are terms applied to the baldness of advanced years. With the loss of hair there is usually atrophy of the other cutaneous structures. In these cases the hairs, as a rule, first turn gray, become dry and thin, and fall out, with no tendency to a new growth. The condition is seen upon the scalp, beginning usually at the crown; in occasional instances other parts of the body may also sooner or later show more or less atrophy of the hairy appendage. Upon the scalp, the skin, which is more or less free of the hair, becomes atrophied, smooth and glossy. The alterations in the cutaneous structures in senile baldness consist of marked atrophy of the sebaceous glands, of the hair-follicles and of the skin itself. The affection is common in men, but is comparatively infrequent in women. No satisfactory reason can be assigned for this. Idiopathic premature alopecia is the term applied to the baldness which begins to manifest itself about the age of twenty-five or thirty. The hairs may fall out rapidly or the loss may take place slowly. In these cases the normal hairs are usually replaced with finer, thinner, and shorter hairs, but finally even these eventually cease to be reproduced, and more or less alopecia results. There is no seborrhoea, and the skin shows no other atrophic change. As a rule, several years elapse before the condition becomes marked. The location affected is the same as in senile alopecia, and the same statement may be made as to its frequency in the two sexes. According to microscopical examination, there is an increase in the connective tissue, compressing the blood-vessels, and thus interfering with the blood-supply of the parts.

Symptomatic premature alopecia includes all those forms of alopecia which are the result of disease, either local or general. Falling of the hair is frequent after fevers and other systemic diseases. Mental anxiety, nervous exhaustion, and depraved conditions of the general health may also cause varying degrees of alopecia. In these cases the shedding of the hair usually takes place rapidly, constituting defluvium capillorum. With a disappearance of the exciting cause there is usually a regrowth, but this is not always the case, as not infrequently the baldness is permanent. Among local diseases which give rise to baldness, chronic seborrhoea is the most important. As a result of the seborrhoea, atrophy of the glands occurs, and alopecia sooner or later sets in. Many other local affections, as lupus erythematosus, erysipelas, variola, tinea tonsurans, and tinea favosa, are at times attended with loss of hair. Syphilitic alopecia may occur at two different periods of that disease. It is noted as one of the early symptoms, and later as the result of the general cachexia, or in localized patches as the result of ulceration and destruction of the skin. The alopecia appearing as a secondary symptom of the disease may be slight or complete baldness may take place, but in either case the loss is rarely permanent if the patient is under proper treatment. As a rule, in the course of a few months the hair is reproduced. The alopecia resulting from ulcerative lesions is permanent.

The treatment of the various varieties of alopecia named depends, as will be readily inferred, upon the etiological causes. Senile alopecia is rarely amenable to treatment. Idiopathic premature alopecia may frequently be benefited by therapeutic measures. The general health is to be looked after. In these cases arsenic in moderate doses long continued may prove of some value. The external treatment has in view the promotion of the nutrition of the skin, which is attained by the use of stimulating applications for the purpose of increasing the vascular supply. The treatment of symptomatic premature alopecia is that of the primary disease. The external remedies and formulæ which are employed in cases of alopecia for their stimulating effects will be found in detail under the head of alopecia areata.

Alopecia Areata.

Alopecia areata (syn. area celsi, alopecia circumscripta, porrigo decalvans, tinea decalvans) is an atrophic disease of the hairy system, characterized by the more or less sudden appearance of one or more circumscribed, variously sized and shaped, whitish bald patches. The scalp is the region most frequently the seat of the disease, but other hairy parts, especially the face in the male, are often invaded, and even the whole surface may be involved. Occurring upon the scalp, one or several patches may be present, which are usually rounded and circumscribed. The hair may fall out suddenly without any previous signs of weakening, the individual awaking in the morning to discover an area of partial or complete baldness on the scalp; or, as is usually the case, the loss of hair takes place insidiously or more gradually, several days or weeks elapsing before the bald patch is of sufficient size to attract observation. The parietal region is perhaps most frequently involved. In most cases but a single patch appears at first, but this usually is followed by others. The areas incline to grow larger and larger, and, as a rule, finally coalesce, eventually the whole scalp, with possibly the exception of a tuft or patch here and there, being bald. In most cases, however, the patches, after reaching a certain size, remain stationary.