hi I have bubbles under my skin on my thumb. They have fluid in them. They are spreading and they itch alot. I went to the doctor. He said it was some sort of skin inflection and put me on Bactrim. I have been on the medicine for 4 days. It doesn't seem to be getting better. It is getting worse because now my skin peeling off on my thumb at the original site of injury. The fluid is sometimes yellow in color and sometimes clear. Any ideas what this it?