I also am on day 3 of an itchy rash all over my body. A friend of mine (who is a nurse) and I have a theory that mine is due to stress from the surgery and having pneumonia post op. The only other time I had hives like this was when I had my baby (29 yrs) ago. My friend felt that both times my immune system was stressed after giving birth and having surgery. My band surgery was on 12/20 so the doctor I saw in the ER yesterday feels it is not the anesthesia, the antibiotic for the pneumonia or the pain meds because it is too far out from these and they would be out of my system by now. I feel the anesthetic takes longer but who knows. I was given benadryl, prednisone and vistaril in the ER. Last night was the worst, I could not sleep because of the itching. Today the rash is lighter and I am itching the most on my breasts and abdomen. I agree with most of the posters to do the benadryl, and cortisone cream. If my rash is not gone by next week, I am going to see my primary physician. Good luck and I hope you stop itching soon.