I don't think this problem can be "cured" as such - sorry. Just make sure that whenever you get a bump or bruise to use lots of arnica cream and if you get a scratch or cut then use something like Bio Oil once the scab has gone to help the mark on its way.

If you have scabs avoid picking or catching them as much as possible and after try using palmer's cocoa butter to help fade them. Normally works a treat. If you dislike the smell of cocoa butter try the unscented variety!

it might be helpful to take a B vit supplement. It comes in various strengths but Ive noticed an improvement in my healing since I began to take it.