sentences:  Mild peels include those using glycolic acid, lactic acid, salicylic acid, Jessner's solution, or a lower concentration (20%) of trichloroacetic acid.These peels only affect the epidermal layer of the skin and can be useful in the treatment of superficial acne scars as well as skin pigmentation changes from inflammatory acne.Higher concentrations of trichloroacetic acid (30–40%) are considered to be medium-strength peels and affect the skin as deep as the papillary dermis.