Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. The burning characteristic of pain and negative Xary findings, essentially rule out broken pain. However, the burning pain and redness of skin is concerning for possibility of skin infection called cellulitis. Since you have been on antibiotic for almost a week with no improvement, it is likely that the bacteria causing infection is resistant to antibiotic you are taking. Blood culture and sensitivity is recommended at this point to identify the bacteria and its response to antibiotics. Please be advised to follow up with the urgent care to discuss your issues and need to switch to another antibiotic. You can also apply mupirocin (antibiotic) ointment to the affected area twice daily. Hope I have answered your query. Let me know if I can assist you further.