Symptoms of Community-Acquired Pneumonia
Community-acquired pneumonia (CAP) typically presents with newly acquired respiratory symptoms including cough, sputum production, and/or dyspnea, especially when accompanied by fever and abnormal breath sounds or crackles on auscultation. 1
Classic Symptoms and Presentation
Core Respiratory Symptoms
- Cough (with or without sputum production) - present in 78.8% of cases 2
- Dyspnea (shortness of breath) - present in 62.7% of cases 2
- Sputum production - present in 57.6% of cases 2
- Pleuritic chest pain/discomfort - present in 52.5% of cases 2
Systemic Symptoms
- Fever (temperature >38°C) or hypothermia (≤36°C) - present in 77.1% of cases 2
- Rigors and sweats 1
- Fatigue and myalgias 1
- Headache 1
Physical Examination Findings
- Tachypnea (elevated respiratory rate) - a key indicator of severity 1
- Abnormal breath sounds - including crackles (rales) on auscultation 1
- Percussion abnormalities - present in 55.9% of cases 2
- Tachycardia - often present in more severe cases 1
Atypical Presentations
In elderly patients or those with compromised immune systems, CAP may present atypically with:
- Confusion or altered mental status 1
- Failure to thrive 1
- Worsening of underlying chronic conditions 1
- Falls 1
- Absence of fever (though tachypnea is usually present) 1
Diagnostic Criteria
The diagnosis of CAP should be considered in patients with:
- Two or more signs/symptoms of pneumonia (cough, fever, dyspnea, etc.)
- Radiographic evidence of infiltrates on chest imaging 3
Chest radiography is valuable for:
- Differentiating pneumonia from other conditions
- Identifying specific etiologies (lung abscess, tuberculosis)
- Detecting coexisting conditions (bronchial obstruction, pleural effusion)
- Evaluating severity (multilobar involvement) 1
Severity Assessment
Indicators for Hospital Admission
- Oxygen saturation (SaO₂) <92% or cyanosis
- Respiratory rate >50 breaths/min in children or >70 breaths/min in infants
- Difficulty breathing or grunting
- Signs of dehydration
- Family unable to provide appropriate observation/supervision 1
Indicators for ICU Admission
- Failure to maintain SaO₂ >92% with supplemental oxygen
- Shock
- Rising respiratory and pulse rates with clinical evidence of severe respiratory distress
- Recurrent apnea or irregular breathing 1
Treatment Options
Outpatient Treatment
For patients without comorbidities:
- Amoxicillin, doxycycline, or a macrolide (in areas where pneumococcal resistance to macrolides is <25%) 4
For outpatients with comorbidities:
- Beta-lactam plus macrolide combination OR
- Respiratory fluoroquinolone monotherapy 4
Inpatient Treatment (Non-ICU)
- Beta-lactam (cefotaxime, ceftriaxone) plus macrolide (azithromycin) OR
- Respiratory fluoroquinolone 1, 5
ICU Treatment
For severe CAP without Pseudomonas risk:
- Intravenous beta-lactam (cefotaxime, ceftriaxone) plus either intravenous macrolide (azithromycin) or intravenous fluoroquinolone 1
For patients with Pseudomonas risk factors:
- Antipseudomonal beta-lactam (cefepime, imipenem, meropenem, piperacillin/tazobactam) plus antipseudomonal quinolone OR
- Antipseudomonal beta-lactam plus aminoglycoside plus either macrolide or fluoroquinolone 1
Prevention
- Pneumococcal vaccination for adults ≥65 years or those 19-64 with underlying conditions
- Annual influenza vaccination
- Smoking cessation 1, 4
Common Pitfalls to Avoid
- Missing atypical presentations in elderly patients where confusion may be the only symptom
- Relying solely on clinical findings without radiographic confirmation
- Delaying antibiotic therapy - first dose should be administered within 8 hours of hospital arrival 1
- Inadequate severity assessment leading to inappropriate site-of-care decisions
- Overuse of broad-spectrum antibiotics when not indicated by patient risk factors
Remember that even with extensive diagnostic testing, a specific etiology for CAP cannot be identified in up to half of all patients 1.