Differential Diagnosis of Pediatric Pneumonia
Key Differentials to Consider
1. Bronchiolitis
| Feature | Bronchiolitis | Pneumonia |
|---|
| Age | Typically <2 years (peak 1–6 months) | Any age |
| Season | Winter / spring | Any |
| Causative organism | RSV (mainly) | Bacterial / viral / atypical |
| Wheeze | Prominent, expiratory | Less common |
| Hyperinflation on CXR | Present | Absent (except viral) |
| Consolidation | Absent | Present in bacterial |
| Signs of obstruction | Prominent | Less pronounced |
| Response to bronchodilator | Inconsistent | Not applicable |
In severe bronchiolitis: high fever, adventitious sounds LESS prominent than in bacterial pneumonia.
2. Pulmonary Tuberculosis
| Feature | TB | Bacterial Pneumonia |
|---|
| Onset | Insidious, weeks–months | Acute (days) |
| Fever | Prolonged low-grade | High-grade, acute |
| Weight loss | Present | Absent (acute) |
| Hilar lymphadenopathy | Common | Unusual |
| CXR | Hilar nodes, patchy infiltrates, miliary | Lobar/bronchopneumonia |
| Mantoux / IGRA | Positive | Negative |
| Contact history | Often positive | No |
| Response to antibiotics | No improvement | Improvement expected |
3. Bronchial Asthma
| Feature | Asthma | Pneumonia |
|---|
| Age | Usually >1 year | Any age |
| Attacks | Recurrent, episodic | Acute single episode |
| Trigger | Allergen / infection / exercise | Infection |
| Wheeze | Bilateral, reversible | Localized, may be absent |
| Family history | Often positive | Usually absent |
| Response to bronchodilator | Consistent improvement | No significant response |
| Eosinophilia | May be present | Absent (unless Loeffler) |
| CXR | Hyperinflation | Consolidation |
4. Foreign Body Aspiration
| Feature | Foreign Body | Pneumonia |
|---|
| History | Sudden choking episode | Gradual onset with fever |
| Wheeze | Localized, unilateral | Bilateral / absent |
| Collapse / emphysema | Localized obstructive emphysema | Absent |
| CXR | Hyperinflation one side, mediastinal shift | Consolidation |
| Diagnosis | Bronchoscopy | Clinical + CXR |
5. Pertussis (Whooping Cough)
| Feature | Pertussis | Pneumonia |
|---|
| Organism | Bordetella pertussis | Various |
| Cough character | Paroxysmal; inspiratory whoop; post-tussive vomiting | Productive / dry |
| Fever | Minimal | High-grade (bacterial) |
| WBC | Marked lymphocytosis | Neutrophilia |
| Age | Any; severe in infants | Any |
| Immunization status | Unvaccinated / inadequately vaccinated | Unrelated |
| Complication | Apnea, pneumonia secondary | Empyema, abscess |
6. Congestive Heart Failure
| Feature | CHF | Pneumonia |
|---|
| CXR | Cardiomegaly, pulmonary oedema, pleural effusion | Consolidation |
| Auscultation | Basal crepitations, S3 gallop | Crackles, bronchial breathing |
| JVP / liver | Raised JVP, hepatomegaly, oedema | Normal |
| History | Congenital heart disease, recurrent episodes | Acute illness, fever |
| Echo | Structural abnormality | Normal |
7. Primary Atypical Pneumonia vs Viral Pneumonia
| Feature | Mycoplasma (Atypical) | Viral Pneumonia |
|---|
| Age | School age / adolescents (>4 years) | Any age |
| Onset | Insidious; 12–14 day incubation | Variable |
| Cough | Dry, prominent | Variable |
| Physical signs | Minimal despite extensive X-ray | Variable |
| Cold agglutinins | Elevated (30–60%) | Negative |
| Treatment | Macrolides effective | Supportive (no antibiotics) |
Causes of Recurrent Pneumonia
Consider underlying disease if pneumonia recurs:
- Cystic fibrosis — Pseudomonas, S. aureus, recurrent exacerbations
- Immunodeficiency — Hypogammaglobulinemia, HIV
- Congenital lung malformation — Sequestration, CCAM
- Foreign body — unretrieved
- Gastro-esophageal reflux — recurrent aspiration
- Primary ciliary dyskinesia — abnormal mucociliary clearance
