I don't know what caused it. I ate a lot of sugar when I was younger and had a lot of metal in my mouth as a consequence of this. Tinea versicolor is probably also a genetic disposition as my older sister and father both had it, perhaps it is a common reaction for our gene pool to the same imbalance caused by improper diet and disordered systems of elimination? I could speculate for a while; I do not know a thing.