For About 3 Weeks, I Have Been Having Swelling, Deep

For about 3 weeks, I have been having swelling, deep pain, and itching in my feet and hands. my big toe was so swollen, I went to the ER. They did labs and because there had been no trauma to the toe, the doctor simply said he could not explain the swelling. It is spreading, and the pain is intense like a tender, tender bruise. I have an appointment with a foot doctor on 5/6/15, but it's in my hands and two of my fingers now and a rash like on the back of my knees and also on the tops of my feet. Please any suggestions?