Small pimples on the back may be related to acne, folliculitis, perifollicular keratosis, etc. They should be dealt with by medication and other treatments depending on the cause. 1. Acne: manifested by the appearance of pimples like small rice grains on the back, which will gradually form inflammatory pimples and eventually grow into red nodules or cysts. It is necessary to apply retinoic acid cream, benzoyl peroxide gel and other treatments. If the patient’s acne is more serious, oral isotretinoin can be taken as treatment, and photodynamic therapy can also be used if necessary. 2. Folliculitis: manifested as red, swollen and raised bumps, with white or yellow pus spots at the tip of the bumps. It can be treated with medicines such as fusidic acid cream and ichthyol ointment. 3. Keratosis pilaris: there will be pinpoint-sized bumps on the skin, the color of the bumps is usually purplish red or dark red, without pain and itching symptoms. Generally do not need special treatment, if necessary, can be used externally Vitamin A acid ointment and other drugs. Because of the many causes, patients should consult the doctor in time to clarify the cause of the disease, and strictly comply with the doctor’s instructions for treatment.