The cystic wall of a coma is a membrane-like structure. As the secretions of the gland cannot be discharged, resulting in a long-term accumulation in the gland, the sebaceous glands are progressively enlarged and cysts are formed as the secretions gather more and more. The tissue surrounding the gland then forms a reflux cyst wall. This cyst wall is a layer of epithelial cells and fibrous connective tissue. The thickness of the wall of the acne vulgaris is about 0.5 mm, and it is somewhat elastic, but it is also easily ruptured. Patients with acne should keep their skin clean, so as to facilitate the opening of sebaceous glands and the discharge of secretions from skin glands, and if the patient’s face is itchy, he should not scratch with his fingernails, so as to prevent scratching the skin, which may be infected and cause other diseases.