Closed mouth acne can be improved by topical medication and chemical peeling. 1. Topical medication: For example, topical retinoids such as retinoic acid ointment and adapalene gel can prevent and eliminate acne lesions by regulating the abnormal process of epithelial keratinization in the sebaceous glands of hair follicles and removing the keratin plugs. 2. Chemical peeling: Use of chemical agents such as fruit acid, salicylic acid, amygdalic acid, etc., to make the epidermis and the superficial dermis partially peeled off, so as to remove acne. In addition, it is recommended that patients with long closed mouth acne go to the hospital in time and follow the doctor’s instructions for treatment to avoid delaying the condition.