Frequent pimples on the back are often a manifestation of acne, which is caused by excessive secretion of oil by the sebaceous glands of hair follicles, abnormal keratinization of hair follicle openings, and Propionibacterium acnes infections, etc. It can be treated with topical or oral medication, and you should pay attention to your daily life regimen. The pathogenesis of acne is related to the increase of androgen level and sebum secretion. As adolescents are in the developmental stage, the androgen secretion in the body is vigorous, which leads to the sebaceous glands producing too much oil, which mixes with the epidermal tissues to block the pores, and coupled with abnormal keratinization of follicle openings, which increases the chances of Propionibacterium acnes infections, and thus leads to the onset of acne. Patients can apply retinoic acid cream to treat mild to moderate acne, which can improve sebaceous gland keratinization, anti-inflammatory, and control hyperpigmentation, as well as medications such as fusidic acid cream. If necessary, oral doxycycline, isotretinoin and other medications. In addition, you should pay attention to the usual good habits, avoid spicy and stimulating food, avoid staying up all night, pay attention to clean. If the symptoms of back acne are not relieved, you should go to the hospital in time, according to the individual situation for targeted treatment, it is recommended to use medication under the guidance of the doctor, do not blindly self-medication, in order to avoid the adverse effects.