Looks like powdery mildew. Very common and unfortunately hard to control. There are commercial sprays you can buy, or I hear about a lot of people treating it with milk. Either way, I would cut off the few leaves where it's most severe, and try to treat the less severe ones. Gloves are not especially necessary, because the danger is to the plant, not to you.

Here's a page with more about the milk- http://www.brighthub.com/environment/green-living/articles/60496.aspx

Good luck!

An oregano oil solution sprayed on fungus will kill on contact.