Acne on the skin of the forehead is also called chronic inflammation of the sebaceous glands of the hair follicles. Localized skin on the forehead stimulates excess secretion of sebaceous glands due to dihydrotestosterone, which is also a type of androgen, resulting in too much free fatty acid in sebum and too little linoleic acid, and bacteria take advantage of the situation, which is Propionibacterium acnes infection, causing acne. In cases like this, it is mainly related to an unhealthy lifestyle, through reasonable and balanced nutrition, regular work and rest, and adequate sleep. In addition, you should pay attention to skin cleanliness and health, eat a light diet with more fruits and vegetables, less oil, less salt, less sugar, quit smoking, limit alcohol, and exercise appropriately to help relax your mind. If symptoms are not relieved, go to a dermatologist for relevant topical treatments or physical therapy. If there is still no relief, choose anti-androgen treatment under the guidance of a doctor.