I've had this twice when my allergies got especially bad. The first time was about
seven years ago conservative treatment didn't work and I did develop reactive airway disease (asthma following a cold). That time it was treated with antihistamines and prescript
ion cough syrup, then an albuterol inhaler and finally Advair, which finally cleared it up after nearly a year.
I started in again with it this summer, and went to my doctor last month. She gave me some cough medicine so I could sleep, and started me on Singulair in addition to my Zyrtec. It seems to be getting better, and now I only have to take the cough medicine if I am outside a lot that day.
I'm also a former smoker, who quit about four years before the first episode. The allergist said it could also have been affected by some residual damage to my lungs from smoking.