Hi, My Son Is Eight Year Old And Has A

Hi, my son is eight year old and has a slim comllexion. We live in the cohntryside. Sice a month ago he'been having a dry cough with itchy back and chest, mainly, and also in internal ears and palate. On doctir's suggestion i made my don undertake some blood exams, that do not confirm allergic deseases ( low IGE value), altough eisinophils rate are over the normal value. My son feels itch only when he coughs. Which could be the cause of such a strange synthoms? What can i do to make my son feel better? Which further exams do my son has to hndertake? Thank you for your prompt resoince. Help this mum, please.