What is the most common viral cause of croup?

Croup, characterized by a distinctive barking cough, stridor, and respiratory distress, is primarily associated with viral infections. Among the various viruses that can cause croup, parainfluenza virus is the most common culprit.

Parainfluenza viruses, particularly types 1 and 2, are known to primarily affect young children and are responsible for the seasonal outbreaks of croup. The pathophysiology involves the virus causing inflammation and edema in the larynx and upper airways, leading to the characteristic symptoms of croup.

While other viruses such as respiratory syncytial virus (RSV), rhinovirus, and influenza virus can also lead to upper respiratory illnesses in children, they are less frequently the primary cause of croup compared to parainfluenza virus. Understanding the viral etiology of croup is crucial for guiding appropriate management and treatment, which may include corticosteroids to reduce inflammation and alleviate symptoms.