How to Minimize Acne Scars on Shoulders and Upper Arms?

What is the best treatment for acne scars (loss of pigmentation, not deep pockets) on the tops of shoulders and upper arms? I am 38 yrs. old, and about 2 years ago, due to a major hormonal imbalance, I had severe acne breakouts on my shoulders and upper arms, which resulted in a lot of "white" scars. I'm VERY self conscious of these scars and hate wearing revealing clothes. I'm looking to minimize the scar's appearance