Black birthmark – nevus of Ota is a kind of dermal pigmentation skin disease, which may be genetically related and is autosomal dominant. It is usually located on the face and varies in color from cyan, greenish gray, greenish black or purple-brown. There are more women than men, and the age of onset has two peaks in infancy and adolescence, of which 61.35% are within 1 year of age. Can black birthmarks be treated? Q-switched ruby and Nd-YAG 1064nm laser are the best choice for the treatment of nevus of Ota. This laser can “recognize” normal skin and precisely reach the lesion in a very short time, so that the pigment can absorb extremely high energy instantly and burst into small particles and be discharged out of the body, which greatly reduces the possibility of pigment residue and achieves a cure effect of The effect of the treatment is 100%, no scars are left, and the skin is completely restored to its normal color. What is the principle of black birthmark laser treatment? How long does it take to cure? Laser is the best way to treat black birthmarks at present. It can penetrate the epidermis to destroy the melanin particles in the dermal melanocytes and make them rupture. The ruptured melanosomes are eliminated by phagocytes and metabolized gradually to achieve the purpose of treatment. The number of treatments depends on the depth and size of the black birthmark. Generally, 3-4 treatments are needed for the more superficial black birthmarks, 5-6 treatments are needed for the moderate ones, and more serious ones usually need more than 6 treatments. With an average interval of 2-3 months between each treatment, each treatment operation takes a short time and leaves no scar after the operation, which can achieve better cosmetic effects. What should I pay attention to in laser treatment for black birthmarks? Avoid exposure to the sun before surgery, if there is pigmentation need to improve after treatment. Local anesthetic (lidocaine cream) can be applied externally before surgery to reduce pain. After surgery, blisters and ulcers may occur, which are normal and should be avoided, and antibiotics or scalding cream should be applied. Physical sun protection is recommended to prevent hyperpigmentation. A few patients have mild pigmentation reactions after laser treatment, which generally do not need to be treated and can subside on their own in 3 months to 6 months.