What Causes Red, Sore And Swollen Elbow?

My elbow is just a little sore to the touch but no other pain. It`s very red and a little swollen. It`s very warm and I feel feverish. I had a small area that was dry skin and I scratched may have got some infection that way? But I don`t have any open/cut skin except maybe when I scratched to hard. Any ideas?