Microdermabrasion uses a device which carefully removes the outer layer of the skin revealing a smoother part of the deper skin. Microdermabrasion when performed on skin that is damaged post scarring from acne will show good improvement with one or two sittings. But in deeply damaged skin multilple sittings may be required. In skin that has suffered scarring due to severe acne, the scars can run deep into the layers of the skin.