What are the top 12 common respiratory infections and their treatments?

Top 12 Common Respiratory Infections and Their Treatments

The most common respiratory infections include community-acquired pneumonia, acute exacerbation of chronic bronchitis, influenza, pharyngitis, sinusitis, acute bronchitis, common cold, and viral upper respiratory tract infections, each requiring specific treatment approaches based on their etiology and severity.

1. Community-Acquired Pneumonia (CAP)

• Causative agents: Primarily Streptococcus pneumoniae, also Legionella pneumophila in severe cases 1
• Treatment:
  • First-line: Amoxicillin (500-1000mg every 8 hours) for 7-10 days 1
  • Alternatives: Tetracycline, macrolides (azithromycin, clarithromycin) 1
  • For severe cases: Consider respiratory fluoroquinolones 1
  • Duration: 7-10 days for uncomplicated cases; 21 days for L. pneumophila or S. aureus infections 1

2. Acute Exacerbation of Chronic Bronchitis/COPD

• Causative agents: Haemophilus influenzae, S. pneumoniae, Moraxella catarrhalis 1
• Treatment:
  • Antibiotics indicated when at least two Anthonisen criteria present: increased dyspnea, increased sputum volume, and increased sputum purulence 2
  • First-line: Amoxicillin, tetracycline derivatives 1
  • Alternative: Amoxicillin-clavulanate, newer cephalosporins, macrolides 1
  • Duration: 7-14 days 1

3. Influenza

• Treatment:
  • Antiviral treatment generally not recommended empirically 1
  • Consider antivirals only in high-risk patients with typical symptoms for <2 days during known influenza epidemic 1
  • Symptomatic management for most cases

4. Streptococcal Pharyngitis

• Causative agent: Streptococcus pyogenes (Group A Streptococcus) 3
• Treatment:
  • Antibiotics only if Group A Streptococcal infection is confirmed through rapid antigen test 2
  • Expected response rate: 80-90% 1
  • Duration: 10 days 1

5. Acute Sinusitis

• Causative agents: Similar to other upper respiratory infections
• Treatment:
  • First-line: Amoxicillin 2
  • Alternatives: Amoxicillin-clavulanate or doxycycline 2
  • Duration: 10-14 days 1
  • Expected response rate: 70-80% (note: 15% resolve spontaneously) 1

6. Acute Bronchitis

• Causative agents: Primarily viral
• Treatment:
  • Antibiotics generally not recommended 2
  • Symptomatic management only
  • Patient education: Cough typically lasts 2-3 weeks regardless of treatment 2

7. Common Cold/Viral Upper Respiratory Tract Infection

• Causative agents: Rhinoviruses (20-30% of cases), other viruses 4
• Treatment:
  • No antibiotics recommended 2
  • Saline nasal irrigation for symptomatic relief 2
  • Cough suppressants, expectorants, and decongestants may provide symptomatic relief 2

8. Chronic Sinusitis

• Treatment:
  • Expected response rate: 30-40% without surgery, 60-70% with surgery 1
  • Duration: Optimal duration unknown 1

9. Viral Respiratory Infections in Asthma/COPD Exacerbations

• Causative agents: Primarily rhinoviruses 5
• Treatment:
  • Focus on managing underlying condition
  • Antibiotics only if bacterial superinfection suspected

10. Aspiration Pneumonia

• Treatment:
  • Duration: 4-21 days 1
  • Antibiotic choice based on suspected organisms

11. Respiratory Syncytial Virus (RSV) Infection

• Treatment:
  • Primarily supportive care
  • More severe in elderly and immunocompromised patients

12. Atypical Pneumonia

• Causative agents: Mycoplasma pneumoniae, Chlamydia pneumoniae 1
• Treatment:
  • Macrolides preferred (azithromycin, clarithromycin) 1
  • Duration: 10-14 days 1

Important Clinical Considerations

When to Refer to Hospital

• Severely ill patients with suspected pneumonia (tachypnea, tachycardia, hypotension, confusion)
• Patients failing to respond to antibiotic treatment
• Elderly with elevated risk of complications and relevant comorbidities
• Patients suspected of pulmonary embolism or lung malignancy 1

Monitoring Response

• Clinical effect of antibiotic treatment should be expected within 3 days
• Fever should resolve within 2-3 days of antibiotic initiation 1
• Patients should be advised to return if symptoms persist beyond 3 weeks 1
• Warning signs requiring immediate attention: fever exceeding 4 days, worsening dyspnea, decreased fluid intake, or altered consciousness 1

Antibiotic Resistance Considerations

• Consider local resistance patterns when selecting antibiotics 1
• Increasing incidence of resistant Staphylococcus, Haemophilus, and Streptococcus infections 1
• Sputum culture in exacerbations helps determine appropriate second-line therapy when initial treatment fails 1

Avoiding Common Pitfalls

1. Overuse of antibiotics for viral infections
2. Failure to consider local resistance patterns
3. Inadequate duration of therapy for specific pathogens
4. Not recognizing when hospitalization is necessary
5. Failing to monitor response to treatment appropriately