About a month ago I feel and punctured my left knee, it did not seem to be that serious, however about two weeks later it start to look like it was getting infected. I am a diabetic so I went to the ER. They gave me some antibiotics and some bacteria ointment and sent me home. About a week later it got considerable worst. I went back to the ER and they admitted me in the hospital. Gave me intravenous antibiotics and kept me for about 2 days. Then did all type of blood work to make sure there was not infection in my blood, they took an Xray, and they took a culture. They did not find anything in my blood and the culture did not show staph. So they sent me home with another antibiotics call doxycline. It looks like the wound is healing, but it hurts so bad, that I cry. Did I mentioned that I had psoriasis on that knee before this happen. In the process of all this all the skin came off my knee and now it seem to be coming back. Can you tell me why it hurts so bad, especially at night.