There are many reasons for acne above the mouth, such as improper diet, high androgen, Propionibacterium acnes infection, herpes simplex virus infection and so on. 1. Improper diet: patients who eat spicy, fried, greasy food for a long time will lead to sebaceous gland secretion, which may lead to acne on the roof of the mouth. 2. Excessive androgens: Excessive androgens in the body can lead to exuberant secretion of oil in the skin, which is common in men, polycystic ovary syndrome, ovarian tumors and other people. 3. Propionibacterium acnes infection: Infection with Propionibacterium acnes on the roof of the mouth can lead to a large number of bacterial growth and reproduction, thus leading to acne on the roof of the mouth. 4. Herpes Simplex Virus: Herpes Simplex Virus infection on the roof of the mouth may be related to factors such as mental stress and immune deficiency, which can lead to localized blisters that can be mistaken for pimples. There are many reasons for acne on the roof of the mouth, and after the symptoms appear, it is recommended that the patient go to the hospital in time to complete the examination, make a clear diagnosis, and give standardized treatment under the guidance of the doctor.