I had my appendix out a week and a half ago and also have hives around all of my incisions. This is actually my third time around with this happening. It happened after my hysterectomy and after my gall bladder. Each time the hives have gotten progressively worse. The other thing that I have noticed is they don’t start popping out until the glue starts coming off. So for the first few days I am fine and they usually start around my navel since that glue plug usually comes loose first and then they pop up around each of the other incisions. I also use Benadryl and hydrocortisone cream without much relief. I have a great many drug allergies and would love to figure out what this one is.