I finished treatment (35 radiation treatments and three doses of Cisplatin) for SCC base of tongue 
HPV+ March 29.  I developed a whited patch on the side of my tongue several weeks after.  It was painful and it seemed like I was always aware of it.  My ENT said it looked like a virus and it would probably go away.  Well, it took about 10 weeks, but it's finally gone!  Good luck!