Suggest Treatment For Deep White Spot On Chin

hi, my name is Partha. I am from Agartala,Tripura, age 35 years. last one month i can see a light white spot in my chin. It is not very deep white...but it is light white. It was small but after little spread and now stagnent. In that zone all beard also become white. How can i get my original skin colour on that place? Please suggest.