My 11 y/o son recently was sick for over a week with fever, severe sore throat and headache. His strep and Mono tests were negative and he was treated with Cefdinir and Bromfed DM. His symptoms improved and was able to return to school this week, however the tiredness and lack of appetite persist and he is now complaining of joint pain and had a mild rash on his arms. My wife and I are monitoring him and encouraging him to get more rest. The antibiotic has been completed for over 24 hours and the rash and joint pain just started this evening. Is there anything else we should do or look into, should we be concerned now or let it ride to see if symptoms increase or settle down? Any insight would be greatly appreciated.