A mild itch is listed as one of the more common side effects. You could also be having an allergic reaction and should inform your doctor for alternative medications.
Any type of opiate can have this adverse affect on people. The percocet has an opiate derivitive in it, which causes the itching and could also cause a rash too.
itis just like heroin or codeine. i have to take Lortab and it doesn't make me itch much but i've seen people where they itch like CRAZY! It's just a side effect.
The reason why Percocet makes you Itch is because you must be suffering from chronic pain and have fibromyalgia. And you must be taking oxycodone, it will take time not to worry.