My friends 5 month old has had a chronic cough, that teeters off towards the end of the coughing fit and it is scratchy sounding towards the end, but barking like during the fit. The Naval doctors have said it is a upper respiratory infection, however the cough has been persistent since birth, but it gets worse every month and the doctors want to wait for him to get better, but he doesn't. What could this be? He was born cesarean on time