White patches on the back may be vitiligo, or it may be caused by diseases such as unpigmented nevus and florid chaff rash. Vitiligo can occur in any part of the body, mainly manifested as white patches on the skin, the color is mostly milky white or porcelain white, the shape is usually round, oval, irregular or linear, and the border with the surrounding skin is clear. Nevus pigmentosus is usually a congenital disease, usually appears at birth or shortly after birth, mainly manifested as the appearance of different sizes, pale white, limited hypopigmented spots on the skin surface, with blurred and irregular borders. Flowering furuncle occurs in sebaceous gland secretion parts, such as the chest, back, armpits, etc. The skin lesions are initially spotty, and can gradually develop into flakes in the later stage, with the color of brown, light brown, light red or white, and the surface is covered with a few scales. White spots on the back may also have other causes, it is recommended that patients go to the hospital in a timely manner, improve the examination, and give targeted treatment after clarifying the cause.