8 yr old with acne.

[greenchicken4me]

My 8 year old son has had increasing amounts of whiteheads on his chin over the last 6 months or so. His chin is really covered in them now and they frequently erupt into pimples. Until a couple of weeks ago he only ever used water to wash his face with, and no moisturiser but now I get him to use clearasil wash twice a day. I have not noticed any improvement as yet. He also has a lot of little white bumps on the backs of his arms, but I don't think its related to the problem with his face. He is becoming upset with his appearance and I don't blame him, acne at 8? Seems a bit unfair! He is not displaying any other signs of puberty except for being more emotional than usuall.
Would really appreciate any feedback on this!