DISCOLOURATION OF THE SKIN.

New Zealand Graphic, Volume XIX, Issue XII, 11 September 1897, Page 382

DISCOLOURATION OF THE SKIN.

Between the cuticle—the epidermis, that is, or scarfskin—and the true skin is a layer of cells which secrete from the blood a dark colouring matter. The black races have this feature most fully developed, but even the lightest are n'ot wholly destitute of it. Its complete absence characterizes the albino, giving ns occasionally a chalk-white negro, the hair, of course, participating in the de;ect. As this pigment is also wanting in the albino’s choroid coat of the eye—normally a dark background for the retina, and essential to clear vision—he is nearly blind except at night. There is often a local absence of pigment, causing white patches on the limbs and different parts of the body. Such a patch on the head may give rise to a solitary white lock amid a full head of dark hair. Some parts of the skin are naturally darker than the rest, and the darker colour may extend far beyond the usual limit and still be purely physiological; but darkcoloured spots often appear on the body as a result of some diseased condition or of exciting causes. The simplest and commonest of such spots are known as freckles. Their remote cause is a peculiarly sensitive skin ; their direct;canse is the light and heat of the sun. Persons with fair skin and hair are most subject to them. The pigment, which in others is uniformly distributed, seems to gather into small rounded spots. Freckles are of little account in children, who had better be left free to run and play in the sunshine; but older persons, besides guarding against unnecessary exposure, may need to increase the tone and nutrition of the skin, which can be done by washing it once or twice a day in tar soap and cold water, and afterwards applying a lotion of borax and rose-water. Here and there a person is troubled with large, irregular patches, most frequent on the face and back of the hands. They are caused by a morbid disintegration of the red blood-corpuscles, the debris being deposited in the scarfskin as pigment. This disintegration is caused by some form of debility, induced by disturbance of one or more internal organs. Treatment must aim to restore the nervous power and the general health. l,ocal stimulants may be applied, as in the case of freckles.

Sometimes this discolouration is spread uniformly oyer the entire body, and is then know as Addison’s disease. Its origin is essentially the same as in the more limited disorder last mentioned, but the extensive destruction of blood-corpuscles give rise to a serious anaemia, or poverty of the blood.