Differential Diagnosis for a 2-Month-Old with Wheezing

Single Most Likely Diagnosis

• Viral Bronchiolitis: This is the most common cause of wheezing in infants, typically caused by the Respiratory Syncytial Virus (RSV). The age of the patient and the presentation of wheezing are consistent with this diagnosis.

Other Likely Diagnoses

• Asthma: Although less common in infants, asthma can present with wheezing. However, a diagnosis of asthma at this age would require recurrent episodes of wheezing and other supportive evidence.
• Gastroesophageal Reflux Disease (GERD): GERD can cause wheezing in infants due to the aspiration of stomach contents into the lungs or through a vagal reflex that triggers bronchospasm.
• Allergic Rhinitis: Allergies can cause wheezing, but in a 2-month-old, this would be less likely unless there's a strong family history of atopy.

Do Not Miss Diagnoses

• Congenital Heart Disease: Certain congenital heart defects can cause wheezing due to pulmonary congestion or increased pulmonary blood flow. Missing this diagnosis could be fatal.
• Foreign Body Aspiration: Although more common in older infants who are mobile and putting objects in their mouths, aspiration can occur at any age and is a medical emergency.
• Cystic Fibrosis: A genetic disorder that can cause respiratory symptoms, including wheezing, due to the production of thick, sticky mucus.

Rare Diagnoses

• Bronchial Atresia or Stenosis: Congenital anomalies of the bronchi that can cause wheezing or respiratory distress.
• Vascular Rings or Slings: Abnormal formations of the aortic arch that can compress the trachea or bronchi, leading to wheezing or respiratory symptoms.
• Primary Ciliary Dyskinesia: A rare genetic disorder affecting the cilia of the respiratory tract, leading to chronic respiratory infections and wheezing.