The causes of back acne in boys may be Malassezia folliculitis and acne. The symptoms can be improved by general treatment and reasonable medication. 1. Malassezia folliculitis: Malassezia folliculitis is an inflammatory damage of hair follicles caused by Malassezia. Treatment should choose good permeability of topical antifungal drugs (such as ketoconazole cream, 50% propylene glycol), can also be supplemented with 2% ketoconazole lotion or 2.5% selenium disulfide shampoo bath. If necessary, oral antifungal drugs such as itraconazole can be combined. 2. Acne: Acne is a chronic inflammatory skin disease of the sebaceous gland units of hair follicles. The main principles of treatment are sebum removal, dissolution of keratin, sterilization, anti-inflammatory and regulation of hormone levels. (1) General treatment: Choose water or suitable cleansing products to remove excess oil, flakes and bacterial mixture on the skin surface, pay attention to oil control and moisturizing, and use mild moisturizing milk externally. Avoid squeezing and scratching the skin lesions with hands. Appropriately limit the intake of high glycemic index foods and milk that may trigger or aggravate acne, keep bowel movement smooth, and avoid staying up all night. (2) Topical medication: antibiotics such as fusidic acid cream can be used topically, and vitamin A drugs such as adapalene gel can also be used topically. (3) Oral medication: Oral antibiotics such as minocycline can be taken, or oral treatment such as isotretinoin. All of the above drugs need to be used under the guidance of a doctor, boys back acne is recommended to go to the dermatology department, to clarify the cause of the standardized treatment.