Pneumonia in Children (Bacterial and Viral)

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | Patient Advice

Definition

Pneumonia is an infection of the lungs characterised by inflammation of the alveoli, leading to fluid or pus accumulation. In children, it can be caused by bacterial or viral pathogens, with clinical features varying by age and causative organism.

Aetiology

Bacterial Causes:

• Streptococcus pneumoniae: The most common cause in children.
• Haemophilus influenzae: More common in unvaccinated children.
• Staphylococcus aureus: Can cause severe pneumonia following influenza.
• Group B Streptococcus (GBS): Common in neonates.

Viral Causes:

• Respiratory Syncytial Virus (RSV): The leading cause in children under 2 years.
• Influenza Virus: Associated with seasonal outbreaks.
• Adenovirus: Can cause severe and prolonged illness.
• Parainfluenza Virus: Particularly in toddlers.

Pathophysiology

The pathophysiology differs slightly between bacterial and viral pneumonia:

• Bacterial: Pathogens invade the alveoli, causing inflammation, exudate formation, and consolidation.
• Viral: Pathogens infect epithelial cells, leading to cell death, airway obstruction, and secondary bacterial infection in some cases.

Risk Factors

Common risk factors include:

• Young age (especially under 5 years).
• Prematurity or low birth weight.
• Immunosuppression or chronic illnesses (e.g., asthma, congenital heart disease).
• Exposure to tobacco smoke or air pollution.
• Attendance at daycare centres (increased exposure to pathogens).

Signs and Symptoms

Symptoms vary depending on the age of the child and the causative organism:

• Cough: May be productive in older children or dry in younger children.
• Fever: More common in bacterial pneumonia.
• Tachypnoea: Increased respiratory rate, often the most sensitive clinical sign.
• Chest Indrawing: Use of accessory muscles to breathe.
• Wheezing: More common in viral pneumonia.
• Fatigue: Generalised tiredness and reduced activity.
• Cyanosis: Bluish tint of the lips or extremities in severe cases.

Investigations

Key investigations include:

• Clinical Assessment: Diagnosis often based on history and physical examination.
• Pulse Oximetry: To assess oxygen saturation levels.
• Chest X-ray:
  • Bacterial: Lobar consolidation or pleural effusion.
  • Viral: Hyperinflation and peribronchial thickening.
• Blood Tests:
  • Full Blood Count (FBC): Elevated white cell count in bacterial pneumonia.
  • C-reactive Protein (CRP): Raised in bacterial infections.
• Nasopharyngeal Swab: To identify viral pathogens using PCR testing.

Management

1. Bacterial Pneumonia

• Antibiotics:
  • First-line: Amoxicillin 40–50 mg/kg TDS for 5–7 days.
  • Penicillin Allergy: Clarithromycin 7.5 mg/kg BD.
• Hospitalisation: Indicated for severe cases (e.g., hypoxia, dehydration).
• Supportive Care: Oxygen therapy if SpO₂ < 92%, and IV fluids if oral intake is poor.

2. Viral Pneumonia

• Supportive Care: Mainstay of treatment, including hydration and antipyretics (e.g., paracetamol).
• Oxygen Therapy: For hypoxia (SpO₂ < 92%).
• Antivirals: Consider oseltamivir for influenza pneumonia within 48 hours of symptom onset.

3. Severe Pneumonia

• IV Antibiotics: Co-amoxiclav or ceftriaxone for bacterial pneumonia.
• ICU Referral: For respiratory failure or shock.

Patient Advice

Key advice includes:

• Ensure adherence to prescribed medications and complete the course of antibiotics.
• Encourage fluid intake to prevent dehydration.
• Seek medical attention if symptoms worsen, such as increased difficulty breathing or persistent fever.
• Maintain good hygiene practices to reduce the risk of respiratory infections.
• Ensure vaccinations are up to date, including pneumococcal and annual influenza vaccines.