I Have Developed A Rash From Ankles To My Knees.

I have developed a rash from ankles to my knees. About 3 weeks ago i cut my leg on the car door. I have been using silerdine patches and washing it with a mild soap. It just started yesterday. I can't narrow it down to a detergent or any treatment I get at the burn center. It is on both legs. Do you have any ideas?? The itching is driving me crazy.