I woke up this morning with a huge (quarter size) white patch on the flap side of my tongue, it is thick leathry and solid. I have had thrush like stuff, that I could brush off with my toothbrush. This wont scrape or brush off, and it seems as although the solid white patch is quarter size, the whole area doesn't look quite right. What should I do. I am not scheduled for a checkup until mid July. Is leukolakia dangerous for us OC surviors. That is what it looks like to me.