You are probably experiencing a healing crisis. This often happens when one starts detoxification. Your body has probably started to release old toxins faster than it can get rid of them, which is why you are experiencing the acne. It's a good sign, ironically enough. It means your body is strong enough get rid of the old toxins and heal itself. To learn more about the healing crisis, you might want to read "The Detox Book" by Bruce Fife. Also, http://www.drlwilson.com
and http://www.arltma.com
have good articles on the topic.