Thanks for your question on Health Care Magic.
I can understand your child's situation and problem.
By your history and description, possibility of allergic disease is more in your son's case.
He might be having
allergic rhinitis and allergic
bronchitis.
Best treatment for this is identification of allergen and if possible complete avoidance of it.
So avoid dust, pollens, chemicals etc.
Continue montair and
budecort. These are first line treatment for allergy and no harm in giving him. These are safe for long term use also.
So you can give them without fear.
Recurrent viral infection with
Influenza virus also trigger allergy. So give your son annual Influenza
vaccination to prevent recurrent infection.
Hope I have solved your query.
Wishing good health to your son.
Thanks.