Here is a good article on RTI and other things that can mimic one.
http://www.anapsid.org/rti.html

Have you changed anything in the past couple weeks, new type of substrate, hides or other furniture?

I spent over a $100 getting my RRS evaluated for a RTI but it was a toxic reaction to a plastic false rock hide for snakes and went away about 3 days after it was removed.

But like the article will tell you, a vet trip ASAP, if it is a RTI waiting will make it worse and harder to treat.