Differential Diagnosis for a 2-Month-Old Patient with Cough and Congestion
Single Most Likely Diagnosis
- Viral Upper Respiratory Tract Infection (URTI): This is the most common cause of cough and congestion in infants, often caused by viruses such as rhinovirus, coronavirus, or respiratory syncytial virus (RSV). The symptoms worsening over the last 2 days could indicate a peak in the viral infection.
Other Likely Diagnoses
- Bronchiolitis: Common in infants, especially those under 6 months, caused by RSV or other viruses, leading to inflammation of the small airways.
- Pneumonia: Can be caused by bacteria or viruses, presenting with cough, congestion, and potentially fever, and is a common concern in infants with respiratory symptoms.
- Allergic Rhinitis: Though less common in infants as young as 2 months, could be considered if there's a family history of allergies or if symptoms persist or recur.
Do Not Miss Diagnoses
- Pertussis (Whooping Cough): A highly contagious bacterial infection that can be severe in young infants, characterized by a distinctive whoop sound during coughing fits.
- Congenital Heart Disease: Though not directly causing cough and congestion, undiagnosed heart defects can lead to respiratory symptoms due to pulmonary congestion.
- Cystic Fibrosis: A genetic disorder leading to persistent lung infections and congestion, among other symptoms, which could present early in life.
Rare Diagnoses
- Foreign Body Aspiration: Though more common in older infants who are mobile and putting objects in their mouths, it's a rare but critical diagnosis to consider in any infant with sudden onset of respiratory symptoms.
- Immune Deficiency: Conditions such as severe combined immunodeficiency (SCID) can lead to recurrent or severe infections, including those causing cough and congestion.
- Anatomical Abnormalities: Such as tracheoesophageal fistula or laryngomalacia, which can cause respiratory symptoms due to anatomical issues rather than infection.