AKT · Respiratory/Respiratory infectionlow yield

Lower respiratory tract infection & acute bronchitis

Usually viral self-limiting airway infection (acute bronchitis); bacterial LRTI without consolidation

Overview

A chest infection without the consolidation of pneumonia. Acute bronchitis is usually a self-limiting viral infection of the large airways (cough ± sputum, often after a coryzal illness) and generally does NOT need antibiotics. The skill is distinguishing it from pneumonia (no focal signs/consolidation) and using antibiotics judiciously (stewardship) — reserving them for higher-risk patients or signs of pneumonia.

Recognise

Acute cough (often productive), preceded by coryza, with wheeze/chest discomfort but NO focal chest signs or consolidation; usually self-limiting (can cough for 3+ weeks)
Generally systemically well, normal or mildly raised inflammatory markers; no high fever/tachypnoea/focal crackles of pneumonia
Most are viral; antibiotics offer little benefit in otherwise healthy adults (antimicrobial stewardship)

Red flags

Focal chest signs/consolidation, high CURB-65 features, or systemic sepsis → it's pneumonia → treat accordingly
Haemoptysis, weight loss or a non-resolving cough → exclude cancer/TB

Differentials & how to tell them apart

Pneumoniafocal consolidation/signs, high fever, tachypnoea, raised CRP — antibiotics indicated

Exacerbation of asthma/COPDknown airways disease with wheeze/breathlessness

Pertussis / post-viral coughparoxysmal cough ± whoop; prolonged post-infective cough

Investigations

Largely clinical; CXR only if pneumonia suspected (focal signs, high fever, tachypnoea) or red flags; CRP can guide antibiotic decisions in primary care; sputum/cultures not routine.

Management

Self-care + safety-netting (no routine antibiotics); antibiotics only if high-risk/pneumonia features

1Distinguish from pneumonia — acute bronchitis has NO focal consolidation/signs and the patient is usually systemically well. Manage with self-care and safety-netting; antibiotics are not routinely needed (stewardship).Gate: Focal chest signs/consolidation or systemic sepsis → treat as pneumonia (CURB-65); offer antibiotics in acute bronchitis only for high-risk/comorbid patients or a CRP/clinical picture suggesting bacterial infection.
2Use a delayed/back-up prescription or targeted antibiotics where indicated; treat any underlying airways disease; exclude cancer/TB for a non-resolving cough.

Self-care + safety-netting (usually NO antibiotics) — reassure (often viral, self-limiting); analgesia/fluids; antimicrobial stewardship

Consider antibiotics if systemically very unwell, high-risk/comorbid, or features of pneumonia — e.g. a delayed/back-up prescription or amoxicillin/doxycycline per local policy; CRP-guided in primary care

Treat the underlying airways disease — if exacerbating asthma/COPD/bronchiectasis

Safety-net for deterioration — return if focal signs/sepsis/persistent symptoms develop

Key points

Acute cough after coryza + NO focal consolidation + systemically well = acute bronchitis/LRTI → self-care + safety-netting, NO routine antibiotics (stewardship). The key step is excluding pneumonia (focal signs/CURB-65) and not missing a non-resolving cough (cancer/TB).

Monitor & prognosis

Symptom resolution, safety-netting for deterioration; reassess persistent cough.

Self-limiting in most; cough can persist for weeks.

Source: NICE NG237 (acute cough/bronchitis); antimicrobial stewardship