When white patches of skin appear on the back, it is first recommended to have a fungal immunofluorescence test. The back is rich in sebaceous glands and abnormal oil secretion, which can easily lead to fungal infection and lichen planus if not washed in time.
If it is lichen planus you can use ketoconazole lotion for local cleaning and oral itraconazole capsules for treatment.
If it is not a fungal infection, the nature of the disease is first diagnosed and secondly symptomatic treatment is administered.