Cystic acne is actually acne vulgaris, which may be related to heredity, androgen-induced sebum secretion in large quantities, keratinization of follicular sebaceous gland ducts, propagation of Propionibacterium acnes, and immune-inflammatory response, etc. Topical medication, oral medication, and physical therapy can be chosen to eliminate it. 1. Topical medication: Vitamin A cream, fusidic acid cream, adapalene gel and other medications can be used externally as prescribed by the doctor to improve severe acne to a certain extent. 2. Oral medication: In addition to topical medication, oral antibiotics, such as cefdinir and erythromycin, can also be taken as prescribed by the doctor, so that the inflammation can be absorbed as soon as possible. 3. Physical therapy: Red and blue light therapy and photodynamic therapy can also improve severe acne, especially acne caused by Propionibacterium acnes infection, through which the growth and reproduction of Propionibacterium acnes can be inhibited. When severe acne occurs, it is recommended that patients need to go to the hospital in a timely manner, and take standardized treatment under the guidance of the doctor, do not use medication indiscriminately, and the above drugs need to be used in accordance with the doctor’s instructions, so as not to lead to adverse consequences.