Diseases with small white spots on the skin include vitiligo, pityriasis alba, idiopathic punctate white spots, and anemic nevi. 1. Vitiligo: it is a common acquired pigment loss skin and mucous membrane disease, which can involve hair follicles and clinically manifest as large white spots or white hair. 2. white chaff rash: a kind of hypopigmented spots that occur in children’s faces, the lesions are round or oval hypopigmented spots of varying sizes, with a few chaffy scales on them. 3. idiopathic punctate white spots: it is one of the expressions of skin degeneration in old age, which is mainly manifested as white spots on the skin with distinct boundaries, mostly pinhead to bean size. 4. Anemic nevus: it is a kind of vascular tissue development defect, belonging to congenital functional abnormality. Clinical manifestations are single or multiple, pale spots of different shapes and sizes. There are many reasons that lead to small white spots on the skin, it is recommended to go to the hospital in time for examination and treatment under the guidance of the doctor.