Which clinical sign is commonly observed in a child with bronchiolitis?

Children with bronchiolitis often exhibit wheezing as a prominent clinical sign. This condition typically arises from viral infections, most commonly respiratory syncytial virus (RSV), leading to inflammation and narrowing of the small airways in the lungs.

Wheezing is characterized by a high-pitched whistling sound that occurs during breathing, particularly during expiration. This sound results from turbulent airflow through constricted airways, which is a hallmark of the airway changes seen in bronchiolitis.

In contrast, barking cough is more commonly associated with croup, stridor indicates upper airway obstruction usually seen in croup or anaphylaxis, and while fever can occur with bronchiolitis, it is not a definitive sign specific to the condition itself. Therefore, wheezing is the most indicative sign associated with bronchiolitis in children.