Define Pneumonia in Children. Describe its aetiology, clinical features, investigations and management.

Definition

• Pneumonia is an acute inflammation of the lung parenchyma (alveoli), usually infective, presenting with cough, fever and fast/difficult breathing.
• It is a leading cause of under-5 mortality worldwide and in India.

Etiology (varies with Age)

• Neonates: Group B Streptococcus, E. Coli, Klebsiella, Listeria.
• Infants & young children: viruses are commonest (RSV, influenza); the leading bacterium is Streptococcus pneumoniae, then H. Influenzae type b and Staphylococcus aureus.
• Older children (> 5 yr): Mycoplasma pneumoniae (atypical), S. Pneumoniae, Chlamydophila.
• Special settings — Staph aureus (post-measles, empyema/pneumatocele), TB, Pneumocystis (in HIV).

WHO / Imnci Classification (cough or Difficult Breathing)

Clinical Features

• Fever, cough, and fast/difficult breathing; poor feeding and irritability.
• Signs of respiratory distress — chest indrawing, nasal flaring, grunting, head-nodding, cyanosis.
• Chest signs — reduced air entry, crepitations, bronchial breathing, dullness (if consolidation/effusion).

Investigations

• Often a clinical diagnosis; pulse oximetry to assess hypoxia.
• Chest X-ray — lobar consolidation (bacterial) or diffuse/patchy infiltrates (viral/atypical); detects effusion/empyema.
• CBC, CRP; blood culture in severe cases; sputum/NP aspirate; Mantoux/GeneXpert if TB suspected.

Management

• Pneumonia (fast breathing): home care with oral amoxicillin (the drug of choice) for 5 days; supportive care and review.
• Severe pneumonia: admit, give oxygen (target SpO2 ≥ 90%), IV antibiotics (ampicillin + gentamicin, or ceftriaxone; add cloxacillin/vancomycin for suspected Staph).
• Supportive care — maintain hydration & nutrition, antipyretics, continue breastfeeding, and treat wheeze if present.
• Switch to oral antibiotics once improving; total course guided by severity and organism.

Complications

• Parapneumonic effusion / empyema; lung abscess; pneumatocele and pneumothorax (Staph).
• Respiratory failure; septicaemia and metastatic infection; SIADH.

Prevention

• Immunisation — PCV (pneumococcal), Hib, measles, pertussis and influenza vaccines.
• Exclusive breastfeeding, adequate nutrition, vitamin A, zinc; hand hygiene.
• Reduce indoor air pollution (biomass smoke) and overcrowding; avoid tobacco exposure.

Pathophysiology

Pathogen reaches the alveoli → Inflammatory exudate fills alveoli (consolidation) → Impaired gas exchange (V/Q mismatch) → Hypoxia, fast breathing & work of breathing ↑

Types / Radiological Patterns

• Lobar pneumonia — consolidation of a lobe (typically pneumococcal).
• Bronchopneumonia — patchy, bilateral infiltrates (common in infants).
• Interstitial / atypical — diffuse pattern (viral, Mycoplasma).

Differential Diagnosis

• Bronchiolitis and asthma (wheeze-predominant); tuberculosis (chronic course, contact history).
• Foreign-body aspiration (non-resolving/localised); congestive cardiac failure; empyema.

Indications for Hospital Admission

• Severe pneumonia (chest indrawing / any danger sign); hypoxia (SpO2 < 90%).
• Age < 2 months; inability to feed/drink; severe malnutrition or significant comorbidity.
• Failure of oral outpatient therapy; complications (effusion/empyema).

Empirical Antibiotic Choice

Supportive Care

• Oxygen to maintain SpO2 ≥ 90%; antipyretics for fever/comfort.
• Maintain hydration and nutrition; continue breastfeeding; small frequent feeds or IV fluids if unable to feed.
• Clear nasal secretions; treat associated wheeze; monitor for deterioration and complications.