My 2 year old son was playing with some older relatives yesterday & ended up with a carpet burn on his back, after he started complaining with it, i took a closer look and noticed a quarter sized red spot that is slightly raised (like a lesion ) on his shoulder , completely round. At first I suspected a ring worn or a bite, but it has no center marks or anything, just completely round & red. Any ideas on what it could be? Should I take him to the doctor or just continue to use triple antibiotic cream on it?