Acne on the back needs to be specifically analyzed according to the patient’s specific situation, there are two possibilities: the first is furunculosis folliculitis, caused by fungal furunculosis infection, before treatment requires laboratory tests for fungi, if it is positive requires antifungal treatment, you can take itraconazole capsules orally once a day, once 2 capsules, oral between half a month to 1 month, topical terbinafine hydrochloride ointment, luliconazole ointment, ketoconazole lotion, terbinafine hydrochloride spray, naftifine ketoconazole ointment, clotrimazole ointment, etc. for treatment. The second type is folliculitis caused by Propionibacterium acnes infection. Before treatment, you can check the Wood’s lamp test, and if it is positive, you need to carry out anti-bacterial treatment, you can use topical clindamycin phosphate gel, ofloxacin gel or fusidic acid ointment.