The black marks left after skin scratching are mainly caused by pigmentation, which can be improved through the use of drugs, picosecond laser, photorejuvenation and other ways. 1. The use of drugs: can be used under the guidance of a specialist doctor hydroquinone cream, vitamin A cream and other drugs, to play a role in inhibiting the metabolism of melanin cells, which can be to a certain extent to lighten the skin after scratching the black marks left. 2. Picosecond laser: the main use of specific energy to reach the subcutaneous, so that the melanin particles destroyed, and then phagocytosis by macrophages, clear, and play a role in getting rid of skin scratching left after the role of black marks. 3. Photorejuvenation: a special light source is mainly applied to make the melanin under the skin destroyed and decomposed, which is conducive to the removal of black marks left after skin scratching. If you want to get rid of black marks after scratching your skin, you must choose a regular hospital to avoid further damage to your skin caused by improper treatment.