Small white spots on the skin are considered to be caused by vitiligo, idiopathic punctate white spots, whiteheads acne and other causes. 1. Vitiligo: when the melanocytes in the skin are destroyed, the lack of melanin causes the phenomenon of white patches on the skin, which can appear in any part of the body, manifesting itself as the symptom of small white spots on the skin. 2. idiopathic punctate white spots: mostly seen in the elderly, due to the degeneration of melanocyte function and the number of reduced, resulting in reduced melanin synthesis in the skin, causing the symptoms of white skin with small white spots. 3. Whitehead pimples: due to the skin follicle funnel part of the skin by the skin in the stratum corneum cells, sebum accumulation blockage caused by the skin appeared pinhead size milky white pimples, mostly distributed in the sebaceous gland secretion of the parts of the skin, manifested in the skin with white small white dots of the symptom. There are many reasons for white dots on the skin, and you should go to the hospital to confirm the specific situation and get targeted treatment as soon as possible.