i went on accutane about 2 years ago for my face..cleared up in about 8 months.. about 7 months ago, i started getting acne again, only this time on my back. but the weird thing about it is its on the sides of my back, and the sides of my body.. my shoulders and upper arms.. picture a tshirt on, is only were the acne is. not anywhere else. i went back on accutane, but had to get off becuase of awful chest pains. so im using benzoyle peroxide, but still isnt helping. i tried wearing new undershirts which are 100% polyester instead of the cotton ones, incase that was it..but still no luck.. any ideas why it only grows there and not anywhere else..