We have a 14 year old with CF and he has had issues with coughing fits when he is playing soccer both indoor and outdoor, participating in PE and even rough housing at home. Last July he cultured aspergillas flavus (fungus) that is found in farm fields on crops, etc for the first time so they started him on an antifungal and changed him from Advair to Qvar. He was on albuteral for the nebulizer, 30 mins. of vest, steroid inhaler (Advair then Qvar) and the same at night expect adding pulmozyme. He did 3 months of the antifungal med and during that treatment he has zero coughing fits while exercising, etc. When we went back to pulmonary in September for our regular 3 month visit he didn't culture the aspergillas. We went to see a allergy specialist in October to see what he was allergic to, guess what, he was allergic to aspergillas and the coughing fits had come back. He was started on Astelin nose spray, continued with Flonase nose spray, changed Zyrtec from once daily to twice daily, upped his dose of Singulair, etc. The coughing fits didn't seem to get better so last month was out 3 months to go back to the CF center. He has a drastic drop in his PFT's from 106 to 86. This is the first time this had ever happened.
He was started on Tobi thru his nebulizer, Cipro, they switched him back to Advair from the Qvar and they started him on hypotonic saline 7%. We did get the culture results back and he was growing aspergillas flavus again. He stared this almost 30 days ago and he goes back to test his PFT's on Friday. I believe the problem that he is having is that he is allergic to the aspergillas that is growing in his lungs so while he is being treated (with a med that can effect your liver) it helps to keep the inflammation down but as soon as he is done with the anti fungal the inflammation is there again b/c of the allergy so he has the coughing fits. The hypotonic saline has really helped him to hack that mucus up and doing huffs has really helped him to get that mucus out.
How is your son with doing his huffs? Has he tried hypotonic saline? I would maybe see about allergy testing with an actual internal med. doctor rather than the CF center. I am looking forward to hearing how your son is doing in the future.