CF or asthama?

So, DS for a couple weeks kept clearing his throat but not really coughing more and not sick...then had a nasty coughing spell after exercising (and also I realized the house was horribly dusty). Dust, vacuumed, and upped his Xopenex to 3x a day, but that's it. Cough had gone away and after the extra dose he hasn't coughed (other than a random passing one and not harsh at all), and the throat clearing has gone almost entirely too. Is that an asthama thing? Or with CF would a cough and throat clearing go away like that with nothing but just adding a Xopenex (no vest, no antibotics, etc?) (It could just be the dust which is a reminder to me to be more on top of it!) Thanks!
Source: Cystic Fibrosis Adults Forum - Category: Respiratory Medicine Authors: Tags: Adults Source Type: forums