From what I gather with the information you have provided, it sounds like your boy had or/ has an infection and should be seen by a specialist right away. I would not take any chances with this. I would try a dermatologist that specializes in rashes and such and if that gets you no where then get another opinion, even if it means traveling to another location or hospital. I know that ring worm will appear as a red ring around the skin area and give a slight fever in most cases. Especially if he has been around pets, they could have spread it to him by a bite. Like I said, I have a 3 yr old little girl whom has had many medical issues and if I were in that predicament, I wouldn't take 'no' for an answer.
Best of luck to you & your family...
Sounds like the child should be hospitalized and ID (Infectious Disease) consulted.
You can also post in the Pediatric and Infectious Diseases Communities.
Thanks a lot for the responses. We took him to his second ER visit on Sunday at AI Dupont/Nemours, a very good Children's hospital in Wilmington DE and they diagnosed him with Lymes disease from a hand bite (the deer tick did not attach at all) and checked for bacterial meningitis, but that was thankfully negative. So we have a month of antibiotics to do and then further checks with a childrens Lymes specialist located via ILADS online directory. A blood test confirmed the Lymes diagnosis yesterday.
Thank goodness you got some answers to the problem.
All the best to you and your little one.