My twins use a product they get from the Dermatologists. It's a cream called Benzomycin. It clears them right up. They use it on their back too!
Another product you may want to try is Pro Active
Solution . I have seen and heard great things about this product.
But like Christine said, you may want to go to the Dermatologist!
Good luck!
I remember those Acne days! Poor kid.