What to do about my sons sinus or respiratory issues

Patient: My son has been on Abuterol (nebulizer) as needed since he was 5 months old after developing a sort of croup cough (barking sound) He can not be diagnosed with Asthma due to his incapability to complete the test. He has also had a VERY dry nose. Every morning, and I mean every morning, he wakes up with a dry nasal passage. His voice sounds like his nose is clogged. I am trying to find a simple solution (like a vaporisor or something) but I am not sure what I should do.

Doctor: