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Pneumonia in Pediatrics
Definition
Pneumonia is an infection of the lung parenchyma (alveoli and/or interstitium). In children, it may be bacterial, viral, atypical bacterial, or mixed. The clinical presentation and management depend heavily on age, immunization status, and severity.
Epidemiology & Key Context
- Pneumonia remains one of the leading causes of childhood morbidity and mortality worldwide.
- Childhood immunizations against S. pneumoniae, H. influenzae type b, B. pertussis, measles, and influenza have significantly reduced incidence.
- The 7-valent pneumococcal conjugate vaccine (PCV7) reduced invasive pneumococcal disease but shifted serotype distribution; non-included serotypes became more prominent.
- Annual influenza vaccination is recommended from age ≥6 months.
Etiology by Age Group
| Age Group | Common Bacterial Pathogens | Notes |
|---|
| Neonates (<1 mo) | Group B Streptococcus, Gram-negative bacilli (E. coli), Listeria monocytogenes | Risk factors: prolonged ROM, prematurity, meconium aspiration |
| 1–3 months | S. pneumoniae, Chlamydia trachomatis, H. influenzae, Bordetella pertussis, S. aureus | Afebrile pneumonitis syndrome (staccato cough) → consider atypicals |
| 3 months – 5 years | S. pneumoniae, H. influenzae (Hib & nontypeable), S. aureus | Most pneumonias in preschool children are viral and do not require antibiotics |
| 5–18 years | Mycoplasma pneumoniae, S. pneumoniae, Chlamydia pneumoniae, H. influenzae, S. aureus | Atypical pathogens become predominant in school-age children |
Viral causes (RSV, influenza, parainfluenza, adenovirus, human metapneumovirus) predominate in children <5 years. Antibiotics are not indicated for viral pneumonia.
Clinical Features
History
- Cough, fever, rapid breathing, difficult breathing — timing and duration matter
- Lower lobe pneumonia or effusion can cause abdominal pain (mimics appendicitis) in young children
- Recurrent pneumonias suggest underlying disease: cystic fibrosis, immune disorders, anatomic abnormalities, foreign body aspiration
- Neonates: assess maternal perinatal history (GBS, HIV, intrapartum fever, ROM)
Physical Examination
Tachypnea thresholds (WHO/clinical criteria):
| Age | Tachypnea | Severe |
|---|
| <60 days | >60 breaths/min | >70 breaths/min |
| 2–12 months | >50 breaths/min | — |
| 1–5 years | >40 breaths/min | >50 breaths/min |
| >5 years | >20 breaths/min | >50 breaths/min |
Count respiratory rate for a full 60 seconds before examination; fever raises RR by up to 10 breaths/min per 1°C.
Other signs:
- Mild/moderate: nasal flaring, intercostal retractions, crackles (rales), decreased breath sounds
- Severe: lower chest indrawing, grunting, cyanosis
- Infants: apnea, grunting, inability to feed = surrogates for dyspnea
- Hypoxia = SpO₂ <90–92% on room air (strong predictor of radiographic pneumonia)
- Toxic appearance and clinician's overall impression are more sensitive than focal auscultatory findings
Diagnosis
Clinical Diagnosis
No single finding is diagnostic; a constellation is more useful. Fever + tachypnea + decreased breath sounds or crackles predicts radiographic pneumonia.
WHO Classification (resource-limited settings)
- Cough + difficult breathing, no other signs → upper respiratory infection
-
- Tachypnea or chest indrawing → pneumonia (treat with oral antibiotics at home)
-
- General danger signs (lethargy, dehydration) → severe pneumonia (parenteral antibiotics)
Laboratory Evaluation
- Routine blood cultures not recommended in healthy children with mild CAP (low bacteremia rates)
- Blood cultures warranted in: toxic appearance, failed outpatient therapy, suspected resistant organisms, pleural effusion
- CBC, CRP, procalcitonin: may support bacterial vs. viral, but not definitive
- Urine testing should be considered in febrile young infants with bronchiolitis (small ↑ risk of concurrent UTI)
Imaging
Indications for chest X-ray in children with suspected pneumonia:
- Diagnostic uncertainty
- Moderate–severe disease or toxic appearance
- Failure of outpatient antibiotic therapy
- Hospitalization required
- Complications suspected (effusion, empyema, pneumothorax)
- Recurrent/persistent pneumonia (follow-up)
Treatment
Supportive Care
- Supplemental O₂ to maintain SpO₂ >90–92%
- Antipyretics; oral/NG/IV fluids for respiratory losses
- Bronchodilators only if wheezing with asthma (do not routinely use in bronchiolitis <24 months)
- Cough suppressants not recommended in children; codeine specifically discouraged (respiratory suppression risk)
- Honey is effective and safe for cough in children with upper respiratory infections
Empiric Antibiotic Treatment by Age
| Age Group | Outpatient | Inpatient |
|---|
| Neonates | Not recommended (admit) | Ampicillin + Gentamicin (or cefotaxime) |
| 1–3 months | Strongly consider admission | Ampicillin or penicillin G; if not fully immunized: ceftriaxone |
| 3 mo – 5 yr | Amoxicillin 90 mg/kg/d ÷ 2 doses (high-dose); if atypical: azithromycin | Ampicillin; if MRSA suspected: add vancomycin or clindamycin; if atypical: add azithromycin |
| 5–18 yr | If etiology unclear: β-lactam + macrolide; if atypical likely: macrolide monotherapy | Same; levofloxacin if growth maturity reached |
Special notes:
- Azithromycin avoided in infants <3 months due to increased risk of pyloric stenosis
- Ceftriaxone is contraindicated in neonates (displaces bound bilirubin)
- MRSA coverage (vancomycin or clindamycin) when S. aureus empyema, abscess, or pneumatocele suspected
- Macrolides cover: M. pneumoniae, C. trachomatis, C. pneumoniae, B. pertussis
Complications
| Complication | Associated Pathogens |
|---|
| Pleural effusion | S. pneumoniae, Mycoplasma, H. influenzae type b |
| Empyema | S. aureus, S. pneumoniae |
| Pneumatocele / abscess | S. aureus |
| Pneumothorax | S. aureus |
| Extrapulmonary (arthritis, meningitis) | M. pneumoniae |
| Hemolytic-uremic syndrome | Systemic complication |
| Hematogenous spread | Mycobacterium tuberculosis |
A child returning with worsening symptoms after treatment → suspect resistant organism, viral etiology, or complications (effusion/empyema/pneumothorax). If initial treatment was supportive, consider secondary bacterial pneumonia.
Disposition
| Setting | Infants | Children |
|---|
| Outpatient | Mild–moderate symptoms, SpO₂ >90–92%, RR <70, feeding well, reliable caretakers | Mild–moderate, SpO₂ >90–92%, no significant tachypnea, feeding well |
| Inpatient | SpO₂ <90–92%, RR >70, retractions/grunting/apnea, poor feeding, dehydration, unable to ensure follow-up | SpO₂ <90–92%, tachypnea for age, retractions/grunting, dehydration |
| ICU | Unable to maintain SpO₂ >90–92% on FiO₂ >0.6, need for PPV (CPAP/BiPAP/intubation), altered mental status, shock/severe sepsis | — |
Automatic admission regardless of severity:
- Neonates and infants ≤90 days
- Suspected B. pertussis (admit under respiratory isolation; risk of apnea)
- Suspected active TB (respiratory isolation)
- Children with cystic fibrosis, sickle cell disease, malignancy, or immunodeficiency
- Social indications (caregiver unable to afford/understand/ensure follow-up)
Recent Evidence
Two recent systematic reviews (2025) are relevant:
- Short-course antibiotic therapy for pediatric CAP (Bolormaa et al., 2025 — Pediatr Infect Dis J) [PMID: 39898624] — supports short-course regimens as non-inferior to standard-length therapy for uncomplicated CAP.
- Complicated CAP in children — updated meta-analysis (Liguoro et al., 2025 — Pediatr Pulmonol) [PMID: 41222098] — updates epidemiology and outcomes of complicated pediatric CAP (empyema, necrotizing pneumonia).
Sources: Tintinalli's Emergency Medicine, 9e (Chapter 128) | The Harriet Lane Handbook, 23rd ed. | Tintinalli's Emergency Medicine, 9e