I'd like to reiterate this could be normal with asthma.  It could be that the infection in your lungs is breaking up and the secretions in there are irritating your airways, causing them to itch.  I had this feeling many times too, although mostly as a kid.  I think it's more common in kids because their airways are smaller (this is also why asthma tends to be worse in kids too).    It usually resolves with time, or sometimes with the use of your rescue medicine.  However, if it doesn't, it might possibly be an early warning sign of an asthma attack, perhaps caused by a new onset of infection.  So if it doesn't dissipate you may need to put your asthma action plan into action.   Rick