Suggest Treatment For Vitiligo On My Lips During Pregnancy

sir,i am 26 year married female,have got vitiligo patch in my both corner of lip and before 5 day i marked a small dot shape white mark in the border of lower lip..am planning for a baby.. so pls advise a good and safe drug for it as am cosmetically much depressed about these patch.. and i wud like to know the reason for it appearance also..kindy suggest