Infection of the lower airways and lung parenchyma — acute bronchitis or community-acquired pneumonia (CAP).
History taking
- • Cough (productive/dry), sputum colour, fever, pleuritic chest pain, dyspnoea
- • Duration, prior antibiotics, vaccinations, occupational exposures
- • Comorbidities: COPD, asthma, smoking, immunosuppression
Examination
- • RR, SpO₂, temperature, BP, HR
- • Chest: crackles, bronchial breath sounds, dullness, ↑ vocal fremitus
- • Look for sepsis, dehydration, confusion (CURB-65)
Red flags
- • RR ≥30, SpO₂ <92%, BP <90/60, confusion
- • Multilobar involvement, pleural effusion, abscess on CXR
- • Failure to respond after 48–72 h of appropriate therapy
Differential diagnosis
- • Acute bronchitis (viral), COVID-19, influenza pneumonia
- • Bacterial CAP (S. pneumoniae, H. influenzae, atypicals)
- • TB, PE, pulmonary oedema, lung abscess, malignancy
Recommended investigations
- • CBC, CRP/procalcitonin, electrolytes, RFT
- • Chest X-ray; sputum Gram stain & culture, AFB
- • Blood culture if febrile/severe; SARS-CoV-2 & influenza PCR
- • ABG if SpO₂ <92%
Diagnosis
- • CAP = new infiltrate + acute respiratory symptoms
- • Severity: CURB-65 (Confusion, Urea>7, RR≥30, BP<90/60, Age≥65)
Initial treatment / management
- • Outpatient (CURB-65 0–1): Oral amoxicillin or doxycycline; add macrolide if atypicals suspected
- • Inpatient: IV beta-lactam + macrolide; ICU if severe
- • Oxygen if SpO₂ <94%; bronchodilators if wheeze
- • Vaccination: pneumococcal + influenza post-recovery
Prescription examples
- • Tab Amoxicillin 1 g PO TDS x 5 d (CURB-65 0–1)
- • Tab Doxycycline 100 mg PO BD x 5 d (penicillin allergy)
- • Tab Azithromycin 500 mg PO OD x 3 d (atypical cover)
- • Tab Paracetamol 650 mg PO TDS PRN
Follow-up advice
- • Review at 48–72 h to assess response
- • Repeat CXR at 6 weeks if smoker, >50 y, or persistent symptoms (exclude malignancy)
Patient counselling
- • Smoking cessation, deep breathing exercises
- • Pneumococcal & influenza vaccination
- • Return immediately if breathlessness or confusion
Referral criteria
- • CURB-65 ≥2, hypoxia, sepsis — admit
- • Suspected TB, lung abscess, empyema, malignancy
Clinical pearls
- • Procalcitonin can help reduce unnecessary antibiotic use
- • Beware of post-influenza Staph. aureus pneumonia
- • Always exclude TB in chronic cough with weight loss
References
- • ATS/IDSA CAP Guidelines 2019
- • BTS Guidelines for CAP in Adults 2009/2015 update
Educational outpatient guide — verify against local guidelines before clinical use.
