Numbness and pain in finger after burn

About seven or eight years ago I suffered a nasty burn to the left half tip of my right index finger (which foolishly, I didn't see a doctor about).

Now, when I look at my fingertip I can see a round completely white part of skin of around half a centimeter in length and width, with the surrounding area being slightly reddish.

My problem is that this part of my finger feels numb and I regularly feel a stinging pain in my fingertip. I'm constantly aware of this annoying numb/stinging feeling and it's getting to the point where I'm avoiding using this finger (when holding things etc.) - it really is that frustrating to me.

What's going on here and would there be anything that can be done about it, considering that the surface of the injury is so very small?