Skin Spot on Leg: Possible Causes & What to Watch For

Question
My husband has had a spot come up on his leg about 3 days ago.  It's red in the center with an almost perfect ring bruise around it.  It feels a little hard to the touch and is sore.  He has a dr's appt in a couple of days but we were just wondering what the possiblities of what this could be are??

Answer
the spot may be simply a small puncture wound and some bleeding occurred and now is spreading out.  Usually insect bites (with the exception of some spiders) will hurt immediately and you will know it.  But, without noticing anything, I suspect he bumped it and didn't think about it and then after the bleeding occurred it started hurting.  On the other hand, if the ring is red, but not a bruise, that can be a "bullseye rash" associated with ticks and lyme disease, but he should have seen an imbedded tick there for well over a day.  hope this helps...