UK Guidelines for Community-Acquired Pneumonia vs Acute Bronchitis
For adults in the community with suspected lower respiratory tract infection, use clinical assessment with severity scoring (CURB-65 or CRB-65) to distinguish pneumonia from acute bronchitis, obtain chest radiography when pneumonia is suspected, and prescribe amoxicillin at higher doses for confirmed community-acquired pneumonia while avoiding antibiotics entirely for acute bronchitis. 1
Initial Assessment and Differentiation
Clinical Features Distinguishing Pneumonia from Bronchitis
Suspect pneumonia rather than bronchitis when:
- Focal chest signs are present on examination (bronchial breathing, crackles, dullness to percussion)
- Systemic features of severe illness exist (confusion, tachypnoea >30/min, tachycardia >125/min, hypotension)
- High fever with rigors
- Pleuritic chest pain
Acute bronchitis typically presents with:
- Cough (with or without sputum) as the predominant symptom
- Absence of focal chest signs
- Self-limiting course lasting 2-3 weeks
- No radiographic infiltrates 2, 3
Severity Assessment for Suspected Pneumonia
Use the CRB-65 score in community settings (1 point each for):
- Confusion (new onset)
- Respiratory rate ≥30/min
- Blood pressure (systolic <90 mmHg or diastolic ≤60 mmHg)
- Age ≥65 years
The CURB-65 adds urea >7 mmol/L but requires laboratory testing, making CRB-65 more practical for community assessment 1. However, evidence suggests further validation of CRB-65 in primary care settings is needed 4.
Patients should be reviewed after 48 hours or earlier if clinically indicated, reassessing these adverse prognostic features 1.
Imaging Recommendations
When to Order Chest Radiography
Obtain chest radiography when:
- Clinical features suggest pneumonia (focal signs, systemic illness)
- Patient meets criteria for hospital referral
- Diagnosis remains uncertain after clinical assessment
Do not routinely image patients with:
- Clear clinical picture of acute bronchitis (diffuse wheeze, no focal signs)
- Mild symptoms without systemic features
The BTS guidelines emphasize that chest radiography is essential for confirming pneumonia diagnosis before initiating treatment in hospitalized patients, with 83% of patients receiving chest x-rays within 4 hours of admission in UK practice 5.
Antibiotic Recommendations
For Community-Acquired Pneumonia in the Community
First-line: Amoxicillin at higher doses than previously recommended 1
Alternative (for penicillin allergy): Macrolide (erythromycin or clarithromycin) 1
Critical caveat: For patients being referred to hospital with life-threatening illness or anticipated delays >2 hours in admission, GPs should consider administering antibiotics immediately 1.
For Acute Bronchitis
Do not prescribe antibiotics 2. The evidence is clear:
- Antibiotics decrease cough duration by only approximately 0.5 days
- They expose patients to unnecessary adverse effects
- Acute bronchitis is self-limiting (2-3 weeks duration)
Management focuses on:
- Symptom relief
- Patient education about expected 2-3 week cough duration
- Describing it as a "chest cold" to reduce antibiotic expectations
- Consider delayed antibiotic prescription strategy if needed to satisfy patient concerns 2
Exception: Test for and treat pertussis with macrolides if suspected (prolonged paroxysmal cough, post-tussive vomiting, inspiratory whoop) 3.
For Hospitalized Non-Severe CAP
Preferred: Combined oral therapy with amoxicillin plus a macrolide (erythromycin or clarithromycin) for patients requiring hospital admission for clinical reasons 1
Amoxicillin monotherapy acceptable for:
- Previously untreated patients in the community
- Patients admitted for non-clinical reasons (elderly, socially isolated) who would otherwise be treated at home 1
When oral therapy contraindicated: IV ampicillin or benzylpenicillin plus IV erythromycin or clarithromycin 1
For Hospitalized Severe CAP
Immediate parenteral antibiotics required 1
Preferred regimen: IV combination of:
- Broad-spectrum β-lactamase stable antibiotic (co-amoxiclav OR second-generation cephalosporin like cefuroxime OR third-generation like cefotaxime/ceftriaxone)
- PLUS macrolide (clarithromycin or erythromycin) 1
Alternative for β-lactam/macrolide intolerance or C. difficile concerns: Fluoroquinolone with pneumococcal activity (levofloxacin) plus IV benzylpenicillin 1
Duration: 10 days for microbiologically undefined severe pneumonia; extend to 14-21 days for legionella, staphylococcal, or Gram-negative enteric bacilli 1
Common Pitfalls and Caveats
Fluoroquinolone Use
Fluoroquinolones are NOT recommended as first-line agents or for community use 1. They may be useful alternatives in selected hospitalized patients, but experience with newer agents remains limited and concerns exist about interactions and side effects 1.
Oxygen Therapy Considerations
For hospitalized patients, pulse oximetry should guide oxygen therapy targeting PaO₂ >8 kPa and SaO₂ >92%. However, in patients with pre-existing COPD and ventilatory failure, oxygen therapy must be guided by repeated arterial blood gas measurements 1.
Follow-up Requirements
All pneumonia patients require clinical review at approximately 6 weeks with their GP or in hospital clinic. Chest radiography at follow-up is indicated for:
- Persistent symptoms or physical signs
- Higher risk of underlying malignancy (smokers, age >50 years) 1
Radiographs need not be repeated before hospital discharge in patients with satisfactory clinical recovery 1.
Guideline Limitations
These recommendations are based on 2001 BTS guidelines [1-1, which were subsequently updated in 2009 and compared favorably with 2014 NICE guidelines 6. While the core recommendations remain valid, clinicians should be aware that local hospital guidelines may vary, with only 55.5% of UK patients receiving antibiotics according to local CAP guidelines in a 2009/10 audit 5.