Definition of Pediatric Pneumonia
Pneumonia is an inflammation of the lung parenchyma involving the alveoli and/or interstitial tissue, resulting from infection (bacterial, viral, fungal, or atypical organisms).
- One of the leading causes of under-5 mortality worldwide
- Classified anatomically and pathologically for clinical utility
Anatomical Classification of Pneumonia
| Type | Description | Common Cause |
|---|---|---|
| Lobar pneumonia | Consolidation of entire lobe | Pneumococcus, Klebsiella |
| Bronchopneumonia (lobular) | Patchy consolidation around bronchi | Staph, H. influenzae, Gram-neg |
| Interstitial pneumonia | Infiltration of interstitial tissue | Viruses, Mycoplasma, Streptococcus |
Pathological Basis
- Consolidation — alveolar exudate fills air spaces (lobar/bronchopneumonia)
- Interstitial infiltration — inflammatory cells in interstitium (viral/atypical)
- Both processes may coexist
Classification by Age Group
| Age Group | Predominant Type |
|---|---|
| Neonates (<1 month) | Gram-negative (E. coli, Klebsiella), Staph, aspiration |
| Young infants (1–3 months) | Gram-negative, Staph, Chlamydia trachomatis |
| Infants (3–12 months) | RSV (viral), Pneumococcus, H. influenzae, Staph |
| 1–5 years | Pneumococcus, H. influenzae, Staph; viral (RSV, parainfluenza) |
| School age / adolescents | Pneumococcus, Mycoplasma pneumoniae, Chlamydia pneumoniae |
Classification by Setting
- Community-acquired pneumonia (CAP) — most common; managed as outpatient or inpatient depending on severity
- Hospital-acquired pneumonia (HAP) — occurs >48 hours after admission; Gram-negative organisms predominate (Klebsiella, Pseudomonas)
- Aspiration pneumonia — kerosene, feeds; chemical inflammation ± secondary infection
WHO ARI / IMNCI Classification (2 months–5 years)
| Category | Key Sign | Action |
|---|---|---|
| No pneumonia (cough/cold) | No fast breathing, no chest indrawing | Home care |
| Pneumonia | Fast breathing ± lower chest indrawing, normal SpO₂ | Oral amoxicillin, follow-up 2 days |
| Severe pneumonia | Chest indrawing + danger signs | Inpatient, IV antibiotics |
Fast breathing cutoffs (WHO):
- <2 months: ≥60/min
- 2–12 months: ≥50/min
- 1–5 years: ≥40/min
Key Risk Factors for Pneumonia in Children
- Low birth weight
- Malnutrition / Vitamin A deficiency
- Lack of breastfeeding
- Passive smoking / indoor air pollution
- Crowding, large family size
- Young age (<2 years)
- Immunocompromised states (HIV, malnutrition, diabetes)