It may be due to androgen secretion, oil secretion and other reasons caused by the front chest and back long pimples, also known as acne, so that the acne marks to create melanin precipitation, can be removed by applying drugs, the use of skin care products to remove. 1. Apply medication: Apply medication that promotes the metabolism and absorption of melanin to the area with acne marks, such as vitamin A cream; you can also apply azelaic acid gel to inhibit the production and spread of melanin. 2. Use skin care products: Regularly use products with exfoliating effects, such as body scrubs, to promote the metabolism of keratinocytes. Regularly clean the skin, clean the pores of the oil and dander, so as not to re-infect the inflammation of acne, cleaned after the appropriate application of whitening effect of the body lotion, lighten the acne marks. Forehead and back acne marks melanin precipitation on the body generally have no effect, the patient can use appropriate medication under the guidance of a physician to lighten the acne marks.