White spots on the arms may be seen in vitiligo, anemic nevi or occupational white spots and other skin diseases. 1. vitiligo: mainly for the later occurrence, its occurrence can be serum with anti-melanocyte antigen autoantibodies, redox imbalance in the lesion area, melanocyte self-destruction and other etiological factors related to the onset of any age, can appear in the whole body in all parts of the size of the various forms of white skin lesions, mainly for the loss of pigmentation spots. 2. Anemic nevus: it is a congenital abnormality, which can be related to vascular dysfunction, and it can occur in any part of the body, with limited white spots of variable sizes, but it does not cause any self-conscious symptoms. 3. Occupational leukoplakia: workers in contact with quinone compounds such as automobile assembly oil in the automobile manufacturing industry and tert-butylphenol, the raw material for manufacturing disinfectants, can have skin pigmentation loss spots and occupational leukoplakia. The appearance of white spots on the arm may also be caused by other reasons, gradually expanding after observation, need to consult a doctor in time to clarify the diagnosis, follow the doctor’s instructions to choose the appropriate treatment.