I have whitish patches on my face. What can be causing them?

The most common: Tinea can cause this. It is a fungi that is on all of us. Some people are prone to this. It can be treated systemically or topically or both, using antifunguals. Another cause is autoimmune vitligo. This is frequently coincident with other autominune problems such as thyroid disease and perncious anemia. In this case tanning makes the areas with vitiligo more visibile.