Can Upper Respiratory Tract Infection (URTI) occur in children less than 2 years old or is it bronchiolitis?

Upper Respiratory Tract Infections Can Occur in Children Under 2 Years Old and Are Distinct from Bronchiolitis

Both upper respiratory tract infections (URTIs) and bronchiolitis can occur in children less than 2 years old, but they are distinct clinical entities with different presentations, management approaches, and prognoses. 1, 2

Distinguishing URTI from Bronchiolitis in Children Under 2 Years

Clinical Presentation

URTI:

• Primarily affects the upper respiratory tract (nose, pharynx, larynx)
• Presents with rhinorrhea, nasal congestion, cough, and possibly low-grade fever
• Minimal to no respiratory distress
• No wheezing or crackles on auscultation
• Normal oxygen saturation

Bronchiolitis:

• Affects the lower respiratory tract (bronchioles)
• Characterized by inflammation, edema, and necrosis of epithelial cells lining small airways 1
• Presents with:
  • Initial rhinitis
  • Progressive tachypnea
  • Wheezing
  • Cough
  • Crackles
  • Use of accessory muscles
  • Nasal flaring 1
• May have decreased oxygen saturation
• Most common in infants 1-12 months, but defined as occurring in children 1 month to 2 years of age 1, 3

Etiology

• Both conditions are predominantly viral in origin
• RSV is the most common cause of bronchiolitis (90% of children are infected with RSV in first 2 years of life) 1, 4
• Other viruses causing bronchiolitis include human metapneumovirus, influenza, adenovirus, and parainfluenza 1
• URTIs can be caused by rhinoviruses, coronaviruses, adenoviruses, and other respiratory viruses

Risk Factors for Severe Bronchiolitis

Clinicians should assess for these risk factors when evaluating respiratory symptoms in infants:

• Age less than 12 weeks 1
• History of prematurity 1, 5
• Underlying cardiopulmonary disease 1, 5
• Immunodeficiency 1
• Young infants (especially <6 weeks) 5

Management Approach

For URTI:

• Primarily supportive care
• Nasal saline and gentle suctioning
• Adequate hydration
• Antipyretics for fever and discomfort

For Bronchiolitis:

• Supportive care is the mainstay of treatment 2, 4
• Supplemental oxygen if SpO₂ <90% 2
• Ensure adequate hydration 2
• Gentle nasal suctioning to clear secretions 2
• Consider high-flow nasal cannula if respiratory distress worsens 2
• Avoid routine use of:
  • Bronchodilators 1, 2, 4
  • Corticosteroids 1, 2, 4
  • Antibiotics (unless specific bacterial co-infection) 1, 2, 6
  • Chest physiotherapy 1, 2
  • Routine laboratory and radiologic studies 1, 4

When to Consider Hospital Admission

Consider hospitalization for bronchiolitis when:

• Persistent hypoxemia (SpO₂ <90%)
• Moderate to severe respiratory distress
• Inability to maintain adequate oral hydration
• Young age (<12 weeks)
• Presence of risk factors for severe disease
• Apnea episodes

Common Pitfalls to Avoid

1. Misdiagnosing bronchiolitis as asthma or pneumonia: Bronchiolitis is a clinical diagnosis based on history and physical examination in children under 2 years 1, 3

2. Overuse of antibiotics: Antibiotics should only be used when there is clear evidence of bacterial co-infection 1, 6

3. Unnecessary diagnostic testing: Routine laboratory tests and radiographs are not recommended for typical cases of bronchiolitis 1, 4

4. Overtreatment with ineffective therapies: Evidence does not support routine use of bronchodilators, corticosteroids, or chest physiotherapy 1, 2, 4

5. Failing to recognize severe disease: Be vigilant for signs of respiratory failure, dehydration, or apnea, especially in high-risk infants 1, 5

In summary, while both URTIs and bronchiolitis can affect children under 2 years of age, they represent different disease processes with distinct clinical presentations and management approaches. Proper differentiation is essential for appropriate treatment and to avoid unnecessary interventions.