Teenagers with back acne can be seen in a variety of diseases, such as shingles, acne, eczema and so on. Clinical treatments are chosen according to the specifics of the disease, and the main treatments include general treatment, medication, and so on. 1. Herpes zoster: It is a skin infection that can be caused by viruses, low immune system and other factors. The main symptoms can be seen in the affected area of the skin appearing pimples, can be accompanied by neuralgia. Treatment includes general treatment and medication, such as keeping the affected area dry to avoid aggravating the infection; topical acyclovir and acetaminophen can be used as prescribed by the doctor to relieve pain. 2. Acne: It is a chronic inflammatory disease that occurs in the hair follicles and is most common in teenagers. It can be caused by androgen metabolism malfunction, increased sebum secretion and other factors. The main symptoms can be seen in the affected area of the skin pimples, papules, etc., can be widely distributed. Treatment includes general treatment and medication, such as eating a light diet and cleaning the skin regularly; topical medication such as adapalene and clindamycin can be used as prescribed by the doctor. 3. Eczema: It is a chronic itchy skin disease, which can be caused by abnormal immune function and genetic factors. The main symptoms can be seen in the affected area of the skin, such as the appearance of millet size pimples, can be distributed in groups. The main treatment includes general treatment, drug treatment, such as finding and avoiding the source of irritation, external use of glycerine lotion, hydrocortisone and other drugs to stop itching. If a teenager’s back is full of pimples, he or she should go to the hospital in time for a relevant examination to clarify the cause of the disease and follow the doctor’s instructions to use medication to treat the disease, and should not treat the disease on his or her own.