Nevus of Ota and nevus of Ito are more likely to occur in colored people, such as oriental people and black people, and the prevalence rate in Japan is 0.3% to 1.0%. 65% of patients have nevus at birth, and the rest mostly appear between 10 and 20 years old, with occasional late onset or occurrence during pregnancy. In Wuhan, China, 4,278 people were examined, and there were 7 cases of nevus of Ota, with a prevalence of 0.16%, and 4 cases were present at birth, accounting for 57.1%. It is more common in women. The lesions are pale cyan, gray-blue, brown-blue to blue-black or tawny patches or spots, with the central part of the patch being dark and the edges becoming lighter. Occasionally, some areas of the pigmented spots may be elevated or even have small nodules of corn to green bean size. The spots are distributed in clusters, with varying density, or with patches in the center and spots on the edges. The color of the lesions is aggravated by sun exposure, exertion, menstruation, and pregnancy. In some cases, the lesions become darker and larger during puberty. The most common sites of involvement are the periorbital, temporal, forehead, zygomatic and nasal flanks, i.e. the area corresponding to the distribution of the second and second branches of the trigeminal nerve; the distribution is unilateral, occasionally bilateral (about 10%), and about 2/3 of patients have ipsilateral scleral blue staining. Treatment of nevus of Ota: nevus of Ota is treated by Q-switched laser, the most frequently used laser is Q-switched ND:YAG laser, the treatment principle is that pigment absorbs laser energy and produces blasting effect, thus removing pigment. Post-operative care: 1. sun protection; 2. oral vitamin C for two weeks; 3. topical medication to promote healing; 4. do not get wet until the scabs fall off.