can be treated with drugs as well as surgically.
Drugs that can be used to treat lip vitiligo are steroids, tacrolimus, placentrex
derived growth factors and psoralens . Photo therapy too can be tried to regain pigmentation. However with these therapies result and time taken to regain pigmentation may vary. I would also like to assert that treatment needs to be continued from months to an year.
However if you feel that medicines did not give you relief and the white patch
has not progressed and has been stable, then these modalities could be tried
1) tattooing of the depigmented area to match it with normal color of your lips
2) surgical procedures like suction blister grafting, melanocyte
transfer etc or simple excision of the white area followed by suturing( if the lesion is small)
Hope that answers your query. Take care.