The causes of long-term chin acne include abnormal androgen levels, increased sebaceous gland secretion, abnormal keratinization of perifollicular cells, Propionibacterium acnes infection, and other triggering and aggravating factors, such as improper diet, psychiatric factors, and improper cleansing. 1. Abnormal androgen levels and increased sebaceous gland secretion are the basic pathological basis for the development of acne. Abnormal keratinization of perifollicular cells leads to clogged pores, and Propionibacterium acnes stimulates the emergence of inflammation, which results in long-term recurrent acne on the chin. 2. Improper diet: If you eat too much spicy and stimulating food, desserts or sweets, drinks, etc., it will prompt the sebaceous glands to secrete more oil, leading to pore clogging and acne. 3. Mental factors: such as excessive stress or mental tension, it is also possible to have long-term chin acne. 4. Improper cleaning: When the facial skin is not cleaned properly for a long time, the sebaceous glands on the surface of the skin secrete exuberantly, and the acne bacteria breed in large quantities, resulting in long-term acne. It is recommended to go to the dermatologist in time and not to blindly deal with it on your own.