I should add I think they started at work a few hours after I wore the pad, because I was sitting and noticed my ankles were incredibly itchy and had raised bumped. I haven't had hives since before high school.
Also, I started taking amoxicillin
about two weeks ago for an ear infection. I have since finished those pills, but I mention this because when I was a kid, I was told I was allergic to the dye in the liquid amoxicillin (banana medicine). I got hives, apparently, when I took it.