Acne on the lips is usually a symptom of acne, herpes simplex, perioral dermatitis or sebaceous ectasia, and needs to go to the hospital for a clear diagnosis before treatment. 1. Acne is mainly caused by keratinization of the skin around the follicular opening of the lips, where sebum cannot be discharged normally and accumulates in the follicular opening to breed Propionibacterium acnes. It is related to heredity, staying up late, eating sweets and spicy food. 2. Herpes simplex is caused by viral infection, transmitted through direct skin contact such as kissing, but also indirectly through masks, towels items. 3. Perioral dermatitis is of unknown etiology, related to contact with mites and fluoride toothpaste, and can be relieved on its own after some patients stop using fluoride toothpaste. 4. Sebaceous ectasia is a benign skin growth, which occurs on the upper lip. It is mainly related to smoking, heredity, local trauma and other reasons, and has no effect on the body. There may be other reasons for pimples on the lips, it is recommended to go to the hospital in time, after a clear diagnosis of symptomatic treatment, do not blindly deal with their own.