What Do Open Sores On Legs, Itchy Feet And Hives On Elbows And Shoulders Suggest?

I have had an open sore on one leg for a month and an open sore that has pretty much healed on the other leg. I have had some itching on my feet and legs for about two months. I developed hives on the back of my elbows and shoulders, the last 3 nights, with itching affecting my sleep at night. The Dr. ran several tests and referred me to a dermatologist. The tests he ran were negative.