White spots on skin are a common form of skin discoloration; they are often a result of loss of pigment. They can happen to any person. It is not related to gender, race, age or climate.
White spots may be caused by skin diseases, such as vitiligo. In this case, there is an underproduction of the skin pigment melanin because of the destruction of melanocytes.
Another possible cause is tinea versicolor. This disease is caused by yeast, and it is worsened by oily or warm skin.
While neither of these diseases are deadly or contagious, skin discoloration is not normal, and it should be discussed with a health care provider.