What are the odd patches on this man's tongue?
A 29-year-old man reports a two-month history of odd patches on his tongue. He says they are essentially asymptomatic but sometimes he has a mild burning sensation when eating hot and/or spicy foods. He also reports that the patches tend to move around on a weekly if not daily basis. He also reports that his mother told him she had a similar condition approximately ten years ago that lasted a year.
What is your diagnosis?