Acne is manifested by acne on the neck. Acne is a chronic inflammatory skin disease of the hair follicle and sebaceous gland unit, which can be suffered by people of all ages, with a high incidence of teenagers. The pathogenesis of acne has not yet been fully elucidated. Heredity, androgen induced sebum secretion, sebaceous gland duct keratosis of hair follicle, propionibacterium acnes reproduction, immune inflammatory reaction and other factors may be related to it. Some patients are also affected by heredity, immunity, endocrine, emotion, diet and other factors. As an independent endocrine tissue of skin, hair follicle sebaceous gland is controlled by sex hormone. After puberty, the increase of androgen level or the imbalance of androgen and estrogen levels in the body can increase the sebaceous glands and the secretion of sebum. Under the action of Propionibacterium acnes, inflammatory reaction will occur, which will damage and break the hair follicle wall. Various hair follicle contents will spill into the dermis, causing inflammation around the hair follicle sebaceous gland units, and a series of clinical manifestations from inflammatory papules to cystic damage will appear.
