In case of herpes zoster on the back, it is recommended to give vaxilovir or famciclovir orally for 7-10 days, along with nerve-nourishing vitamins B1, B6, B12 and vitamin E orally. Those with significant pain can be given painkillers orally, such as aminoglutethimide, and topically, mainly to avoid infection, povidone-iodine solution or penciclovir gel can be given topically. The best results are generally achieved when the medication is administered within 72 hours of the appearance of the rash. If the rash is a single rash in a cluster, herpes simplex is more likely to be considered. The treatment for herpes simplex is also to give antiviral vaxilovir or famciclovir orally, usually for 5-7 days, without the need for nerve-nourishing drugs, and topically can also be given penciclovir gel or povidone-iodine solution for external use.