Chin acne may be related to endocrine factors, keratinization of follicular sebaceous gland ducts, and propagation of Propionibacterium acnes. 1. Endocrine factors: endocrine disorders in the body may trigger an increase in the level of androgens, leading to exuberant secretion of sebaceous glands, which in turn leads to chin acne. 2. Keratinization of follicular sebaceous gland ducts: abnormal keratinization of follicular sebaceous gland ducts on the chin can lead to narrowing of the follicle opening, making it difficult for local sebum to be discharged from the body, which may lead to acne. 3. Propionibacterium acnes reproduction: sebum provides oil and an anaerobic environment for the growth of microorganisms such as Propionibacterium acnes, which can induce an inflammatory response that may lead to the appearance of acne. There are many causes of chin acne, and patients are advised to go to a regular hospital to clarify the cause.