The Effect of Copper in Vitiligo'

Recently many studies have been made to show that copper plays an important role in pigmentation. The initial observation dealing with the action of copper in this respect was an incidental finding made by Keil and Nelson (1) in 1931. While experimenting with rats in the study of nutritional or milk anemia, which is essentially a copper deficiency disease, these observers noted that the color of dark-haired animals changed to a silvery gray after the rats had been maintained on a milk diet for a number of weeks. In the same year, Cuningham (2) made three important observations relevant to this problem. First, he noted that the skin of black-coated animals was apt to contain more copper than that of white-coated ones; second, that the copper content of the skin was concentrated mainly in the epidermis; and thirdly, "in vitro" experiments demonstrated the fact that copper accelerated the oxidation of dopa by skin extracts containing dopa-oxidase. Nothing further was added to our knowledge concerning the action of copper in pigmentation until Gorter (3), in 1935, conclusively demonstrated the fact that copper-free diets resulted in depigmentation of the hair of rats, rabbits, and cats and that this depigmentation disappeared following the administration of copper. On the other hand, no effect on melanogenesis was obtained if other minerals or vitamins were added to the diet. The young rat was the animal most susceptible in demonstrating this action. In the same year Sarata (4) made the first definite attempt to correlate the copper content of the skin with its degree