Considering a facelift, but I have Vitiligo.

I have successfully treated patients with vitiligo without negative impact on this autoimmune disease. Although there will never be 100% certainly, it is very reasonable to plan your facelift procedure. I would make sure though that the disease is not progressing at the time of your surgery. 

Vitiligo is a condition where melanin cells are destroyed.
The cause is unknown so a decision such as cosmetic
surgery may be difficult. I am not aware of cases where
a facelift operation may have cause worsening of the
condition. You may want to consider time to document
that the Vitiligo is stable prior surgery. Usually about 3 years. 
A team  approach between your dermatologist and a board 
certified plastic surgeon may be beneficial. Best wishes.