Hi. I had surgery done on my finger last Tuesday and have developed what looks like severe hives or rash from the elbow down to my wrist. It's been 4 days and it doesn't seem to be getting better. I've been taking some benadryl tablets, but only 1 - once a day. They had used some sort of tourniquet on my arm which left nasty bruises, but they are better but the hives are terrible, ugly, red, and raised, very itchy. What could have caused this. I did not take any prescription pain meds, just some ibuprofen the first 2 days.