How Should I Manage Severe Itching That Is Causing Welts On My Head Or Arms While On Oxycodone And Xarelto After An Ankle Replacement Surgery?

i recently had ankle replacement surgery. i was prescribed oxycodone and xeralto. within a couple days i started itching, first my head then my arms, like it was slowly moving down my body. if i scratch it it does become red and raised. i ve taken benedryl and put cortisone cream. no fever or swelling in the throat. but this itching is making me crazy and making my recovery a nightmare.