Acne is actually a clinical manifestation of acne, which is clinically divided into blackhead acne and whitehead acne. Blackheads are open pimples, and because the follicle opening is open, it may oxidize when in contact with outside air, plus outside dust, etc. It manifests as black pimples. Whiteheads are also called closed pimples, which are those without an opening. The creams used to treat acne are mainly drugs containing retinoic acid, commonly used are adapalene gel, tazarotene gel, and retinoic acid cream, etc. These creams are recommended to be used at night, and must be applied point to point on the acne lesions, not on normal skin. It is important to note that these creams can cause irritation, even a little redness and mild surface flaking, which are normal.