I have had an itchy bump on the back of my thigh for a couple of months now. I don't recall being bitten at all, so I don't even think it is a bite but it doesn't seem like a rash as there is only one. It is about the size of a normal mosquito bite but it is white, and hard..And has a sort of ring in the middle, just tiny pink spots forming a ring. Has anyone experienced this type of thing before?