Hi,
The white spots in skin can be caused by a yeast called
tinea versicolor, vitiligo, other systemic illness. The
tinea versicolor yeasts are always around us, and usually cause no problems. Some of us are more susceptible to the things that can convert tinea versicolor yeast into forms that cause the rash: heat, oily skin, birth control pills, humidity, pregnancy and corticosteroids.
Tinea versicolor yeasts are not contagious.