Skinned knee very hot, swollen all around and very painful

I fell off my motorcycle a week ago, and thought I just skinned my knee. Then it got pretty swollen, and the back/inside area of the knee felt bruised. The swelling went away, so I went to a club last night to do some dancing, and I woke this morning with a knee that was very hot, swollen all around the kneecap, and very painful to move or touch. How can I reduce this?