Ok, I'm in North Central Texas (Forney) playing paintball when I get hit in the knee.  I look and my knee is especially red and stinging (unlike a normal paintball hit.)  Moments before, I had been kneeling and laying in the grass in this slightly wild wooded area.  So, I think it was a coincidence that I was hit by a paintball in a place where something had just scraped my knee.  There were visible red scrapes on my knee.

I didn't think much of it until 2 days later when I noticed my knee had broken out in a rash that reminded me of Poison Oak minus the itching.  After another couple of days, I have had a couple of spots that popped up on my left arm.  Anyway, I'm clueless to what this might be and I'm hoping for some input.