What Type of Doctor Can Help my Knuckle Scar Removal Procedure?

I fell off my bicycle years ago and developed a scar on my knuckle. I started picking and even biting it and it now looks horrible. It is an inflated lump that resembles a strange wort. I have seen a dermatologist and they gave me a cream calling it a "triscoptic scar" or something. The cream would peel off a layer so I was to use only a little at a time. It stung so I quit. What type of doctor handles this and can I get surgery to remove it? It is on my engagement hand and I need quick results.