(Grayness of the hair; Blanching of the hair; Gray hair; Poliosis; Whiteness of the hair).
Definition. An atrophic affection of the hair, characterized by circumscribed or general lack or loss of normal pigment.
Symptoms. This condition may be described as congenital or acquired. The former is very rare and may appear as a part of the general absence of pigment in the tissues known as albinism, or it may bear no relation to that condition and appear only as a patch among the normal colored hair.
Acquired canities, or grayness of the hair, is usually seen in advancing years and is too common to cause much comment. But when it occurs before thirty-five years of age it is deemed premature. There is, however, a well-known difference in families or even among members of the same family in this respect. Males strongly resembling the maternal parent may retain the normal color of the hair years longer than those bearing the stronger paternal likeness, and less frequently vice versa. Canities may be symptomatic of such diseases as syphilis, alopecia areata, peripheral neuroses or leucoderma, but it often occurs without any definite relation to any other disease. While it may appear suddenly or gradually, affecting a small part or becoming more or less general, usually the change noted is progressive and permanent, first showing on the head, often about the temples and before grayness is noted in the beard. Rarely the latter may show the first change, or the condition may coexist with an early whitening of the scalp hairs. Other regions may be involved at a later period.
Sudden and permanent bleaching of the hair has been reported as due to mental shocks, such as severe fright or grief. A similar temporary condition may arise from disorders of the nervous system such as I noted in a case of organic brain disease. In this instance the beard turned completely white, only to be restored to its normal color on the relief of the cerebral symptoms, remaining unchanged until death which occurred a few months later.
Ringed hair is a rare peculiar alternate whitening of short sections of the pilary growth, while the color and other features of the hair remain normal in the intervening areas.
Color changes, other than whitening, may be due to trophic influences. Thus, a change is seen after general falling of the hair from some acute or exhausting disease; the new hair being more or less changed in color. Circumscribed loss of hair may be followed by new hair of a different color as is often observed in the first hair growth on a patch of alopecia areata. While nervous or mental influences occasionally cause changes in the color of the hair, most discolorations are produced by the local chemical action of medical or tonsorial applications, such as chrysarobin, resorcin, capsicum and chloral. Chemicals used in a number of occupations may cause hair changes. Thus, green hair is occasionally seen in workers of copper, blue hair in cobalt or indigo laborers and black hair in coal miners.
Etiology and Pathology. Heredity may be a factor in premature canities and is probably a constant influence in the congenital form. Besides the specific causes mentioned before, age is the chief cause of canities after middle life, but at any period, worry, excessive dissipation, trauma, overwork or general disturbances of nutrition may hasten the condition. The pathological process is in the nature of a trophoneurosis and is the result of a lack of pigment produced in the hair-papillae or it may be due to the presence of air in the cortex of the hair. Both of these factors are causal in many cases.
Prognosis and Treatment. It may be safety said that the condition is progressive and permanent although a few cases have been reported where there has been a return of color. It is not proper at any time or stylish in these days to dye one’s hair, but this is practically the only treatment, if it may be called such. Many of the local measures recommended are not only useless but objectionable and dangerous. In any event, dyeing should not be recommended. If insisted upon, the following may be used:
To obtain a black color (Kaposi):
Rx Argent., nitrat.,
To obtain a brown shade (Kaposi);
Rx Acid. pyrogal.,
Leonard recommends: No. 1 Rx Bismuth. citrat.,
M. Sig. Apply in the morning.
Rx Sodii hyposulphit.,
M. Sig. Apply in the same evening.
Internal remedies and physiological measures to improve the general health may prevent premature grayness or postpone its early development. Graphites, Kreosotum, Lyco., Phosphorus, and Phosphorus acid have been recommended.