I had the same problem this past weekend. I was cleaning out my closet that was very dusty. Big mistake, forgot to use the inhaler first. Dust always knocks my breathing out of wack and I will cough for two or three days like crazy. I just use my Proventil (albuterol), 2 puffs every 4-6 hours until I get it back under control. As long as I feel I am not gasping for air, the coughing usally stops once I have gotten the allergens out of my lungs and nose. I also rinse my nose out 2-3 times a day with Ocean saline nasal spray.