A white hair on the face may be caused by physiological factors, vitiligo, pigmented nevus and so on. 1. physiological factors: the absence or dysfunction of melanocytes within the hair follicle can not synthesize melanin, hair due to the lack of melanin and appear white. If only one white hair on the face, may be the face of individual hair follicle aging caused by local hair follicle melanocyte destruction lack, or lead to black cell dysfunction caused by. 2. Vitiligo: Vitiligo is an acquired skin and mucous membrane disease associated with skin pigment loss. It is mainly manifested by white patches on the skin, and if there are white patches on the face, there may also be localized white hairs. 3. Pigmented nevus: pigmented nevus is a benign neoplasm of the skin caused by the proliferation of nevus cells, clinically manifested as the color is mostly dark brown or ink black, and may appear to have a white hair on the face. Clinically a white hair on the face, there may be hypopigmented skin disease, inflammatory skin disease and other causes, the patient should consult the doctor in time, clear diagnosis and treatment.