Pimple marks are mainly scar tissue left by acne, usually divided into four categories: black pimple marks, red pimple marks, atrophic pimple marks and hyperplastic pimple marks. 1, black acne marks: black acne marks start from the pigmentation after the inflammation of acne, and will gradually disappear with the passage of time. The black pimple marks can be introduced by L-vitamin C type essence plus ultrasound, or use fruit acids to speed up the black pimple marks recede; 2. Red pimple marks: red pimple marks are caused by inflammation of the cells of the original acne place vasodilatation, and the blood vessels are not completely contracted after the acne goes down, forming a temporary red spot, and the symptoms are more obvious when the skin temperature rises or sports. Usually it will gradually recede within half a year, and can also be accelerated by strong pulse light to eliminate acne marks; 3. Atrophic acne marks: when the acne inflammation is more powerful and injures the collagen of the dermis, it can cause the dermis to collapse and leave hollows. The pimples can be squeezed in an incorrect way, leading to pus infection, which can also leave scars. Once produced will not disappear automatically, treatment means fractional laser, etc.; 4, proliferative acne marks: proliferative acne marks are usually determined by congenital physique, is a kind of excessive hypertrophy scars, manifested as obvious red protrusion, will slowly become larger because of scratching or external stimulation. Hyperplastic acne marks mostly occur in patients with overactive fibroblasts in the dermis of the skin, overreacting in the wound healing process, resulting in inflammation and injury of the dermis instead of being concave and convex, turning into hypertrophic skin tissue hyperplasia, which can be treated by local subcutaneous injection of steroid medication.