This is just a guess, but since prednisone is prescribed with RAI for folks with eye problems (to protect the eyes from further damage), I’m thinking it’s only a good thing for you now, not a bad thing.
Call your doctor if you’re anxious and see what he/she has to say.
I’ve had numerous drug allergies and they’re no fun. I usually tough it out with just Benadryl and frozen bags of corn, so that may be an option if your reaction isn’t too severe. Let your doctor be the judge of that–no point in taking risks, but no point in being afraid, either.
Hope you get to feeling better soon,
Melinda