White spots on the skin can be caused by sun exposure or conditions including milia, vitiligo, or pityriasis alba. The spots appear when there is a loss of skin pigment or from trapped skin cells.

A common disorder of the skin, pityriasis alba occurs primarily in children between the ages of 3 and 18 years. The condition usually manifests as dry, fine-scaled, pale patches 0.5 to 6 cm in ...