http://www.sneezwheezdoc.com/education.html
These guys are great, they combine allergy expertise with asthma expertise, which I think is key.
They have us charting our peak flow measurements morning and night to really understand triggers, and watch stability.

Our ds had the nagging cough 'nuisance cough' someone called it...recurring sinus infections related to allergies and unexplained lethargy. Recovery after a cold took forever. Now things are looking up considerably.
We tried several inhalers before landing on one for daily use that works really well, combined with allergy med and flonase for histamine blocking. In addition to that, a fast acting inhaler for right before exercise or if symptoms flare up.

This page links to some articles/sites. Good luck!

https://twitter.com/asimom, https://contributingfactor.wordpress.com