CVS makes an acne body scrub with 2 % salicylic acid that's helped me, but I've been on (and now, for about six months, off) Accutane for a while. I get smaller occasional zits and once in a while a moderate cyst but it's nothing like it used to be. Unfortunately I still have little red nodules on my chest (I think I might have irritated my skin with a depilatory, though...erabarrassing).
I used the same things I did on my face--benzoyl peroxide (though it does bleach sheets and clothes, so be warned) and hydrocortisone cream (for bigger cysts)--on my back and shoulders, as well.