I've been using Retin A micro since 1/31 for cystic acne and was told to cleanse gently and not to exfoliate, because Retin A is an exfoliator. My acne is getting under control but can someone suggest something to brighten up this dull appearance my skin has taken on? Can an AHA be used with Retin A Micro? If so, which one? What else can I be using?