well, i first noticed it the next day but was still kinda tipsy and in a rush to get somewhere and thought it was a scrape or something. then the next day, I looked at it because it was still bugging and it was about a 2" long water blister, just puffed the fuck up and filled with liquid. then on monday or something, my friends that were over said that one of them got poison oak and I was like, "hmm...maybe...but oh, nevermind, this happened before he was exposed to PO". So I just let it go. It stayed puffy for a few days then my pants rubbed against it and made it burst so I washed it and put some neosporin on it when i got home from work that day. It's been red and had a little bit of a fever the whole time and I can feel kind of a hardness about 3" around it. There's a fairly significant (to me) hole in the center that's kind of scabby and dry skin on the other bits. It's still red and the pain is radiating towards the back of my knee a little. Not terrible, but there.