What is the most likely diagnosis for a child with wheezing, coughing, and respiratory distress following an upper respiratory infection?

The most likely diagnosis for a child presenting with wheezing, coughing, and respiratory distress following an upper respiratory infection is bronchiolitis. This condition, often caused by viral infections, especially respiratory syncytial virus (RSV), typically manifests in younger children, particularly those under 2 years of age. After an upper respiratory infection, symptoms may progress to wheezing and difficulty breathing due to inflammation and narrowing of the small airways (bronchioles), which is a hallmark of bronchiolitis.

Croup, while also characterized by respiratory symptoms following a viral infection, primarily presents with a distinctive barking cough and stridor due to upper airway obstruction from inflammation, rather than wheezing. Pneumonia can also cause coughing and respiratory distress, but it is usually associated with fever and findings on examination or imaging that would suggest a lung infection rather than the wheezing pattern seen in bronchiolitis. Asthma typically has a long-term component, with recurrent episodes of wheezing and coughing that might not be directly linked to a recent upper respiratory infection in very young children.

In this context, a diagnosis of bronchiolitis aligns best with the clinical presentation and age of the child following a preceding upper respiratory illness.