Closed mouth is also known as closed acne. When closed mouth appears, it is recommended to go to the hospital to deal with it through topical medication, chemotherapy and physical therapy. 1. Topical medication: Under the guidance of a professional doctor, topical application of retinoids, such as isotretinoin cream and adapalene gel, can help dissolve acne and improve sebaceous gland duct keratinization. Azelaic acid gel can also be applied to kill Propionibacterium acnes and dissolve acne. 2. Chemotherapy: A common treatment is fruit acid peeling. The main use of fruit acids to interfere with the binding force of the cell surface, thereby accelerating the shedding and renewal of epidermal cells, to achieve the purpose of the treatment of occlusion, according to the patient’s tolerance level and the severity of occlusion to configure the appropriate concentration. 3. Physical therapy: Red and blue light and other light therapies can help inhibit sebum secretion and kill Propionibacterium acnes, thus improving the phenomenon of follicle hyperkeratosis and treating occlusion. All in all, it is recommended that patients should seek timely medical advice from their doctors to choose the appropriate way to deal with their closed mouths, as well as to reduce the intake of stimulating foods and keep the skin clean during the treatment period.