What causes acne only on chin? i've read so many theories like stomach problems, liver problms, hormones, eating wrong food.....what is true?

Acne: Acne is a skin condition that occurs when your hair follicles become plugged with oil and dead skin cells.These factors can trigger or aggravate an existing case of acne, hormones, medications, and a diet with a lot of dairy and carbohydrate-rich foods.You can also prevent new acne breakouts with self-care measures by washing your skin with a gentle cleanser and avoiding touching or picking acne.