Most of the rotten mouths are caused by herpes simplex virus infection, and the main symptom is small pinprick-like blisters of varying sizes at the corners of the mouth. For such herpes, we have to apply acyclovir antiviral ointment locally, and the herpes will subside on its own in a week or so, and nutritional support should also be given to improve their resistance. If the patient is caused by eating allergic food, drugs caused by neurovascular swelling, or even neurological erythema, this herpes must be promptly isolated from allergic drugs or food, while taking anti-allergic drugs to promote the healing of the mouth. If the patient is exposed to strong sunlight, we must promptly avoid light, while you can apply light saline or local anesthetic drugs to reduce the pain of the traumatic area.