What is white pityriasis

White pityriasis belongs to a mild dermatitis, is also constitutional eczema dermatitis. Born in spring and autumn, its children, adolescents more common, adults rare, no symptoms or mild itching. Focus more distributed in the face, and forehead, shoulders and upper arms can also be shown. Skin lesions for round or oval plaques, coin size, pale color, dry surface, and with a small amount of gray scales, scratching when there may be scales flying off, basal inflammation slight. Lesions can gradually expand with the development of the disease, and adjacent ones can fuse with each other.