Review Question - QID 212678

An 11-month-old baby boy is brought to the emergency room by his parents for vomiting. His mom reports that he has had a cold for the past week with a runny nose and low-grade fevers. However, his condition worsened today when he began coughing and struggling to breathe. During one of his coughing spells he threw up his milk as well. The parents deny any sick contacts, changes in diet, or bowel changes but endorse fatigue and decreased appetite. A physical examination demonstrates a healthy-looking baby with an intense cough and significant inspiratory stridor. What is the pathophysiology of this patient’s condition?