Acne on the back is a manifestation of acne, or it may be folliculitis; the causes of acne include poor lifestyle, environmental stimulation, over-production of sebaceous glands, folliculitis, and so on. 1. Bad lifestyle: If you often eat spicy and stimulating, high-fat food, it may lead to back acne. If you don’t wash your back skin when you take a bath, it may lead to accumulation of sweat and oil, causing acne. In addition, stress or stay up late for a long time can also cause acne. 2. Environmental stimulation: If the back is in a hot and humid environment for a long time or there is toxic dust in the environment, it may cause back acne. 3. Excessive sebaceous gland secretion: If the sebaceous gland secretion on the back is too exuberant, it will block the exit of the pores, resulting in acne in the area. 4. Folliculitis: If the patient’s back hair follicles are invaded by bacteria or germs, it may lead to hair follicle infection, which is manifested as reddish follicles, pustules at the top of the follicles, and hair in the middle of the follicles, and is accompanied by obvious pain. It is recommended that patients with back acne consult a doctor in a timely manner to clarify the cause of the disease, and strictly follow the doctor’s instructions for treatment.