Acne on both sides of the mouth may be folliculitis, acne, etc. The causes of different diseases are different. 1. Folliculitis: Inflammation of hair follicles mainly caused by bacterial and fungal infections, the most common being Staphylococcus aureus. If the skin is damaged, the bacteria will enter the skin and cause infection. 2. Acne: The onset of acne is related to androgen levels and increased sebum production. For example, abnormal androgen levels during puberty can lead to large amounts of sebum secretion and blockage of hair follicle openings, resulting in the formation of acne. If you have acne at the corners of your mouth, it is advisable to go to the hospital to have the cause clarified and then follow the doctor’s instructions for treatment.