Back acne may be Malassezia folliculitis, bacterial folliculitis, acne, etc. You can apply topical medication, oral medication, and some of them need physical therapy. 1. Malassezia folliculitis: decreased immunity or long-term use of glucocorticoid drugs can cause Malassezia to overpopulate the hair follicles. In this case, you should stop using hormone drugs, improve immunity, pay attention to hygiene, and at the same time, topical amorphophane ointment and other treatments, and if necessary, oral itraconazole and other treatments. 2. Bacterial folliculitis: mainly infected with Staphylococcus aureus, there will be red papules centered on hair follicles, can be used to apply fusidic acid ointment, mupirocin ointment, and serious cases need to be combined with doxycycline, cefuroxime and other drugs. 3. acne: this is a sebaceous gland development androgen levels have a close relationship with the disease, high incidence in adolescence, seborrhea more patients with more obvious symptoms. For more area to the systematic use of drugs, such as oral isotretinoin, doxycycline, etc., at the same time, topical application of adapalene, tazarotene gel and so on. It can also be combined with photodynamic therapy to reduce the inflammatory response. It is recommended that the back acne timely to the hospital, follow the doctor’s instructions standardized treatment, do not self-medication.