<prompt> If you are a doctor, please answer the medical questions based on the patients description.I have a 4yr old son who for the past 5 days has had fevers from as low as 100.2 and as high has 105.2. he has complaint of headaches to the point of not getting off of the couch for over 2hrs. We have taken to his primary care physician who believed he had the start of an ear infection and gave him an antibiotic, he continued to get worse vomitted three times and had a nose bleed. We are at day 6 and he is again running a low grade fever having very limited appetitie if any at all and continued complaint of a headache. I am starting to get concerned Any suggestions as to my next step?  <response>: Hi, If I were your treating Doctor for this case of severe headache and fever under the left rib cage, I would come up with three possibilities:1. I would first rule out serious conditions as meningitis. You should consult hi at neurologist, or You can discuss this with your treating Doctor.2. The second possibility is of Infectious mononucleosisherpes infection, causes by ABV, CMV,HHV 6 type. Try having Acyclovir 30 mgkg divided for 2 times for 5 days. Diagnosis can be confirmed by blood test, IG M, G to ABV, CMV,HHV 6.3. The last possibilities are of sinusitisthyroiditis, GI infection, UTI. I suggest you for differentiation perform blood, urine tests, stool analyses. Hope this answers your question. If you have additional questions or follow-up questions then please do not hesitate in writing to us. I will be happy to answer your questions. Wishing your baby speedy recovery and good health. 