Community-Acquired Pneumonia (CAP)
CAP is an acute infection of the lung parenchyma acquired outside the hospital. In children, the etiology varies significantly by age group, which dictates the choice of empirical antibiotic therapy.
1. Common Etiology by Age
| Age Group | Most Common Pathogens |
|---|---|
| Neonates | Group B Streptococcus, E. coli |
| 1 month – 5 years | Viral (RSV, Parainfluenza), Streptococcus pneumoniae |
| > 5 years | Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae |
2. Diagnostic Approach
- Clinical Signs: Tachypnea is the most sensitive sign. Other signs include fever, cough, chest retractions, and grunting.
- WHO Criteria: Defined by the presence of cough or difficulty breathing + tachypnea (Age < 2mo: ≥ 60/min; 2-11mo: ≥ 50/min; 1-5yr: ≥ 40/min).
- Imaging: CXR is not routine for mild cases but is indicated for severe illness or suspected complications (e.g., empyema, effusion).
3. Management Principles
- Outpatient: Amoxicillin is the first-line antibiotic of choice for suspected bacterial pneumonia.
- Inpatient: IV Ampicillin or Penicillin G for severe cases; switch to Macrolides (e.g., Azithromycin) if atypical pneumonia is suspected (especially in older children).
NEET PG Hint: Remember the “Age-based etiology” rule—this is the most frequently tested concept. Also, recognize that viral pneumonia is far more common than bacterial pneumonia in children under 5 years old, so avoid unnecessary antibiotic use in mild viral cases.