What is Vitiligo?

QUESTION: I know my condition is called vitiligo, but I know little else
about it. I am under treatment that is long, but I can't see any results yet.
Can you offer me some explanations and information?
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ANSWER: Your disease is not all that rare as it affects about 1% of the
population, touching patients of all sexes, ages and backgrounds. At least
half the patients report a family history of vitiligo or other problems with
skin pigmentation. Vitiligo is a disorder of the coloring or pigmentation of
skin where the cells which produce color (they are called melanocytes) are
destroyed for reasons which remain unknown. This results in patches of skin
which are lighter than the surrounding areas, and which can occur anywhere on
the body, predominantly on the backs of hands and wrists, face and neck, and
around body openings. Repigmentation may occur without treatment, but when it
doesn't, treatment is directed at stimulating the production of cells that
produce the color. A medication called psoralen is used in conjunction with
ultraviolet light. It's a long process, as you have discovered, and can
require more than 100 treatments in some cases. About 75% of treated patients
will have a satisfactory result, although total recoloring is never achieved.
Cosmetics may help cover the remaining areas or newly developed tanning
solutions that do not wipe off on clothing may be used.