Differential Diagnosis for 20-month-old Male with Increased Fevers, Congestion, and Cough

Single Most Likely Diagnosis

• Viral Upper Respiratory Tract Infection (URTI): This is the most common cause of fever, congestion, and cough in a child of this age group, especially with no recent sick contacts. The symptoms presented are typical for a viral infection, which is often self-limiting.

Other Likely Diagnoses

• Acute Bronchiolitis: Common in infants and young children, especially during the winter months, caused by respiratory syncytial virus (RSV). Symptoms include fever, cough, and congestion.
• Pneumonia: Can be caused by viral or bacterial pathogens. Symptoms include fever, cough, and difficulty breathing. The absence of recent sick contacts does not rule out pneumonia.
• Influenza: Although there are no recent sick contacts, influenza can still be a consideration, especially during flu season. Symptoms include high fever, cough, and congestion.

Do Not Miss Diagnoses

• Bacterial Pneumonia: While less likely than viral causes, bacterial pneumonia (e.g., caused by Streptococcus pneumoniae) is a critical diagnosis not to miss due to its potential severity and need for antibiotic treatment.
• Pertussis (Whooping Cough): Especially if the cough is severe or has a characteristic whoop, pertussis is a diagnosis that must be considered, particularly if vaccination status is incomplete or unknown.
• Severe Acute Respiratory Syndrome (SARS-CoV-2): Given the ongoing pandemic, COVID-19 should be considered, even in the absence of known contacts, due to its potential for severe disease and the importance of public health measures.

Rare Diagnoses

• Tuberculosis (TB): Although rare in this age group and presentation, TB can cause chronic cough and fever. It would be considered if there was a known exposure or if the child did not respond to typical treatments for viral or bacterial infections.
• Cystic Fibrosis: Presents with recurrent respiratory infections, but the diagnosis is typically made based on a combination of clinical findings, family history, and diagnostic testing (sweat test).
• Immunodeficiency: Conditions that affect the immune system can lead to recurrent or severe infections. This would be considered if the child had a history of frequent or severe infections.