Sun exposure can cause vitiligo, some children after a week of military training, the exposed parts of the face began to appear vitiligo; or some patients go to the wilderness hiking in the sun for a whole day or go to the beach to play in the sun for a whole day, the exposed skin will appear red and swollen, flaking, red spots on the face, arms, red spots flaking after the appearance of white spots, and then more and more. Because of the long time exposure to the sun, melanocytes will deplete and apoptosis, leading to vitiligo. So it is recommended that vitiligo patients should not be exposed to the sun for a long time, otherwise it will cause the activity of the disease.