Thank you for your query.
Now that is not a cause of concern.
I think your child has a problem of allergy
You need to to a Xay of the sinus
and a serum IgE level.
If those tests are abnormal specific treatment is required.
Prevent your child from extremes of climates,pollens,dust,smoke,animals,furs.
If you have any further queries you are free to consult me.
Hope this answers your query.
Wishing your child a speedy recovery.Have a nice day.