if its on the top layer of your skin, just ride it out and let nature take its course. We shed and renew our top layer of skin every month or so. so just give it a month or two and u'll see the marks diminishing. if u had acne on ur back, the last thing u want to do is dermabrasion to aggravate things. trust me, so many times i've gone too greedy or over-perfect i end up messing up my skin even more. big regrets, big regrets. i've learned it the hard way, and i don't think you have to follow my path if u just live with these top-layer deep scars for a few months. good luck.