A child with an RSV infection presents with decreased air entry bilaterally, fine expiratory wheezes, and coarse wet crackles. The most likely diagnosis is?

A child with an RSV infection presents with decreased air entry bilaterally, fine expiratory wheezes, and coarse wet crackles. The most likely diagnosis is?

• A. Croup
• B. Epiglottitis
• C. Pertussis
• D. Bronchiolitis

Answer: (D)

The signs point to bronchiolitis caused by RSV, which is common in young children. In bronchiolitis the small airways become inflamed and filled with mucus, leading to obstruction that is most evident during expiration. That obstruction produces fine expiratory wheezes, while the mucus and inflammation in the tiny airways generate coarse wet crackles as air moves through secretions. Decreased air entry on both sides fits the overall picture of diffuse airway involvement and air trapping/atelectasis seen in this condition. Other infections have different hallmark features: croup typically shows inspiratory stridor and a barky cough; epiglottitis presents with drooling, dysphagia, and a toxic appearance; pertussis is characterized by paroxysmal coughing with post-tussive emesis or a whoop.

The signs point to bronchiolitis caused by RSV, which is common in young children. In bronchiolitis the small airways become inflamed and filled with mucus, leading to obstruction that is most evident during expiration. That obstruction produces fine expiratory wheezes, while the mucus and inflammation in the tiny airways generate coarse wet crackles as air moves through secretions. Decreased air entry on both sides fits the overall picture of diffuse airway involvement and air trapping/atelectasis seen in this condition.

Other infections have different hallmark features: croup typically shows inspiratory stridor and a barky cough; epiglottitis presents with drooling, dysphagia, and a toxic appearance; pertussis is characterized by paroxysmal coughing with post-tussive emesis or a whoop.