Vitiligo runs in my family. I saw it migrate from my grandfather's hands to his face, and now my mother has it up to her wrists. My chances of getting it are excellent.
It generally shows up in body folds (like the armpit), around orifices, and on the knees, face and hands. Sometimes the depigmentation appears spontaneously, sometimes after emotional or physical stress. It can even go away for some patients. The affected skin is highly prone to sunburn, and must be protected, no matter what the original skin tone was. There is also a correlation between vitiligo and premature hair graying.
On the bright side, vitiligo isn't contagious, doesn't itch and doesn't hurt. It is a purely cosmetic disorder.
Personally, I agree with ifeeldizzy that vitiligo can be beautiful. The mottling reminds me of the fur of a calico cat. But then, I was severely burned on the legs about ten years ago, and am already tortoiseshell from that, so I've worked through any mutilation anxiety I had.
Unfortunately, a lot of people with it are very sensitive about their condition. Usual manners apply (don't stare if you can help it; it's better to ask them frankly about it than to ogle from a distance.)
Based on my reading, there are two ways to treat vitiligo.
- Darken the patches affected. This can be done with "tan in a can", various types of makeup, or PUVA treatment.
- Lighten the surrounding skin. Depending on your skin colour, this can be surprisingly effective. Many vitiligo sufferers stay out of the sun, or use high SPF sunblock. In extreme cases, medical treatment can eliminate all skin pigmentation in a patient. This is rarely done.