My son is 8 yrs. old. He has been diagnosed with asthma by a pediatric pulmonologist since he was about 1 yr old. He has a chronic barking cough that won t go away (he has had it since birth). Now a new Ped. Pulmonologist says he was misdiagnosed and he thinks he may have tracheomalacia and wants to do a larngoscopy. He also found a nasal polyp during the exam that has never been seen before. I believe the cough may be more related to undaignosed allergies or the nasal polyp. Should we do the scope or find another opinion? What else could it be?