I'm a 32 year old, healthy male. 4 years ago I was in a serious accident and have had to take Percocet for my pain ever since. For a long time I was on 8 per day, then 6, and now I take 4 per day.
I've never had any reactions/side effects to taking the medication, however about a month ago I started getting really itchy after taking the medication and a rash started to appear on my forarms and chest. The doctor gave me cream and the rash went away.
2 weeks ago I additional back surgery, and my medication was increased to 6 per day. Now I'm getting really itchy every time I take the medication and a burning rash has appeared all over my body.

Is it the Percocet causing this reaction? How could I have no side effects for 4 years, and all of a sudden start now? I'm awaiting a spinal cord stimulator to help with my pain and hopefully get me off the medication, but in the mean time is there something else that I could take for pain?