Closed-cell acne and open-cell acne are both early manifestations of acne, but the main difference lies in the formation mechanism and performance. 1. Characteristics of the formation mechanism: Although they are both early manifestations of acne, caused by the accumulation of sebum and keratin plugs at the mouth of hair follicles, the characteristics of their formation mechanisms are different. Closed pimples are closed pimples, also known as whitehead pimples, which are yellow sebaceous keratin plugs; open pimples are open pimples, also known as blackhead pimples, which are caused by the oxidation of sebaceous keratin plugs. 2. Performance: Although they are all conical pimples consistent with hair follicles, closed acne is often a white pimple at the tip; open acne is oxidized to become a black pimple at the tip of the sebaceous plug. If there is any discomfort, it is recommended to seek medical attention and treatment.