What Causes Itchiness In Body After Undergoing C-section?

I'm a 22 year old female. I had a baby in March of 2009 via C-Section. I was given Duramorph in my epidural first, and then in my IV. Almost as soon as the Morphine was placed in my IV I began itching, everywhere. It has now been over a year since, and I'm still itching. My Dr. (ARNP/CNM) has told me she doesn't think it is related, and even put me on Atarax (sp?) to try to control the itching. (Which did not work.)I have been to a Dermatologist, and they said they cannot find anything wrong.Is it possible that maybe my Dr. is incorrect, and it is still some effects of the Morphine?