Differential Diagnosis for Hyperinflation on CXR with URI, Not a Smoker, and No SOB

• Single Most Likely Diagnosis
  • Asthma: This is a common condition that can cause hyperinflation on chest X-ray (CXR), especially in the context of an upper respiratory infection (URI). The lack of smoking history and absence of shortness of breath (SOB) do not rule out asthma, as it can be asymptomatic between episodes or have a variable presentation.
• Other Likely Diagnoses
  • Viral pneumonia: Although less common, certain viral pneumonias can cause hyperinflation, particularly in children or young adults. The presence of a URI increases the likelihood of a viral etiology.
  • Bronchiolitis: This condition, often seen in children, can result from a viral URI and lead to hyperinflation on CXR due to small airway obstruction.
• Do Not Miss Diagnoses
  • Pneumothorax: Although the patient does not have shortness of breath, a small pneumothorax could potentially cause hyperinflation without significant symptoms. Missing this diagnosis could lead to serious consequences if the pneumothorax were to expand.
  • Foreign body aspiration: This is a critical diagnosis to consider, especially in children, as it can cause hyperinflation of the affected lung or lobe due to air trapping. It requires immediate attention to prevent complications.
• Rare Diagnoses
  • Cystic fibrosis: While less common, cystic fibrosis can present with hyperinflation on CXR due to chronic lung disease. It's more likely in patients with a history of recurrent infections or failure to thrive.
  • Congenital lung anomalies (e.g., congenital lobar emphysema): These rare conditions can cause hyperinflation of a lung lobe and may present with or without symptoms, depending on their size and location.