Amelanotic nevus: This disease occurs at birth or shortly after birth in infants and is present in both sexes. The lesions are often distributed along the nerve segments and appear as limited or generalized hypochromic spots with irregular, non-pigmented edges, which are not as obvious as vitiligo. Pigmentless nevi can be divided into three types according to the distribution of lesions. Isolated type: single white spot, round or oval. Segmental type: The lesions are distributed according to nodules, involving one or more nodules, or along the Blaschko line. Systemic type: It is a white spot involving the whole unilateral limb, with a bizarre pattern of swirling and streaking white spots, resembling spattered white paint. This disease needs to be differentiated from vitiligo and anemic nevus: vitiligo is an acquired disease with late onset, while anaplastic nevus has an early onset. Vitiligo has clear borders and pigmented bands at the borders, while anaplastic nevus has inconspicuous borders and no pigmented deepening, and the white spots persist throughout life. Anemia nevi can occur either after birth or during childhood or later. It is a single or multiple round, oval or irregular light-colored spots. When pressed with a slide, they are not easily distinguished from the surrounding whitened skin, or when rubbed with the hand, the surrounding skin is red, but the light-colored spots are not.