Pigmented scars are formed after trauma, a skin presentation style, and the surrounding skin is basically flush, the surface is smooth and even, glossy, deepening color, most of the difference with the surrounding pigment is not big, a few dark brown, and the surrounding skin difference is big, can also be in the same scar pigmentation has dark and light, the scar surface has no pores and texture and other normal skin structure, generally no itchy and painful symptoms, and also has no functional impairment. Although pigmented scars do not have any functional impairment, but once formed there will be a lot of trouble, especially in the face, it is even more collapse. So what are the reasons for the formation of pigmented scars? 1, the skin is traumatized. Scar pigmentation loss is after the skin is subjected to greater stimulation, (such as burns, surgery) the melanocytes in the skin die in large quantities, unable to secrete melanin normally, resulting in loss of pigment. The skin with pigment loss is mostly white or silvery white, such as the skin after surgery or burns will appear white phenomenon. 2.Inflammation of the skin. Some pigment loss phenomenon is caused by inflammation, post-inflammatory pigment loss is caused by the primary history of disease, such as acne, eczema, dermatitis, psoriasis and other symptoms of melanin deficiency, acne caused by loss of pigmentation scars are generally temporary, the area will not expand. And eczema, dermatitis, psoriasis caused by white spots at the beginning of the beginning of the area will continue to expand, basically can not be self-recovery, but also easily confused with vitiligo. 3, pathology angle reason. Skin in the process of trauma, injury to the dermis below, the dermis in the presence of a large number of melanocytes abnormal secretion and the formation of varying degrees of hyperpigmentation and pigmentation loss. 4.Other factors. Wound healing process of skin tissue structure is not stable, poor adaptability to the environment, improper sunscreen, cleaning, external sensations, diet, etc. will cause wounds appear hyperpigmentation. After producing pigmented scars with ultra-picosecond laser can be improved, the operation process is safe and painless, the process is very fast.