As your child is having on and off fever since 1 year and the blood and urine work up was normal as you told except for high WBC count
. So each time fever focus of infection should be looked into like any throat infection
, urinary tract infection
, any cough or any soft tissue
infections like abscesses. As fever is on and off and not a prolonged one it may be due to discrete infections . But better to investigate with complete blood picture, complete urine examination, malarial parasite, ESR, mantoux test
if suggestive and FNAC of swollen neck glands for histopathology once after consulting your doctor to rule out any significant underlying problem.