Canities (Synonym: Grayness of the Hair.)
Describe canities.
Canities, or graying of the hair, may occur in localized areas or it may be more or less general; the blanching may be slight, scarcely amounting to slight grayness, or it may be complete. It is common to advancing years (canities senilis); it is seen also exceptionally in early life (canities præmatura). The condition is usually permanent. The loss of pigment takes place, as a rule, slowly, but several apparently authentic cases have been reported in which the change occurred in the course of a night or in a few days.
What is the etiology of canities?
The causes are obscure. Heredity is usually an influential factor, and conditions which impair the general nutrition have at times an etiological bearing. Intense anxiety, fright, and other profound nervous shock are looked upon as causative in sudden graying of the hair.
Give the treatment.
Canities is without remedy. Dyeing, although not to be advised, is often practised, and the condition thus masked.