I quit smoking 7 months ago, nothing wrong for first 5.5 months, only cravings. The I get this cough, it lasts for 6 weeks, just an irritating tickle cough. Productive but feels dry hence I cough. Not a cough your lungs up type of cough, just a clear tickle type of cough.Have had xrays and test but all say nothing wrong. It is really annoying, It started after a 13 hour flight, runny nose and dry sinus for several weeks then turned into a cold. Cold cleared in 7 days and left me with the tickle. You have any ideas??