Earlier today I noticed my knee was red and blotchy, it looked like it could have been a rash initially because it appeared to be spreading down my leg. I thought it could have been dehydration so I began drinking water. After about 30-45 minutes it seemed to be going away. About 10 hours later I noticed my knee becoming dis colored again. I had reconstructive surgery on my knee about two and a half weeks ago so I'm not sure if that has something to do with it.