It isn't an allergy casanova, all opioids cause histamine release. I take an antihistamine with mine, although its not always completely effective, and some opiates cause more itching than others. My oxy doesn't really do it enough to bother me, but codeine is a right bugger for it.
My only allergies are to penicillins and presumably other beta-lactam antibiotics, and possibly, although unconfirmed a mild allergy to tetracyclines.
