Wuhan Leaf Plastic Surgery Expert: Anyone with special qualities may form keloids as long as his skin is slightly damaged, such as mosquito bites, vaccination, folliculitis and acne. Local factors include inflammation after trauma, foreign body stimulation, excessive tension and so on. Laser therapy principle: by changing the focusing characteristics of laser, the laser spot becomes a spot, and then the spot is scanned according to a certain pattern by a pattern generator, so that the high heat generated by the laser spot instantly removes the target tissue in the scanning range. Disadvantages: only the protruding skin can be removed, and the sunken place cannot be filled. Improper use of laser can also produce new scars or uneven spots. Principle of skin rubbing method: apply the cooling agent to the numb skin of the affected area, and then polish it with a rotatable instrument to flatten the repaired skin surface. Disadvantages: easy bleeding and pain, rough skin; The skin turns black after exposure. Reminder: Scars can only be repaired and cannot be removed.