Synopsis
Assess cough persisting beyond the expected acute period by wet or dry quality, onset, age and red flags; identify foreign body, suppurative lung disease and aspiration; use targeted radiography and spirometry; and avoid indiscriminate antibiotics, acid suppression or asthma treatment.
- Definitions vary: paediatric respiratory pathways commonly investigate daily cough beyond 4 weeks, while traditional BTS terminology calls more than 8 weeks chronic. Use trajectory and red flags rather than waiting for a label.
- First branch is wet versus dry. A wet cough indicates airway secretion even when a child swallows sputum; parent-recorded audio or video can improve description.
- First-line assessment is detailed history, examination, chest radiograph and spirometry with bronchodilator response when age and ability permit.
- Ask onset, choking, cough-free intervals, nights, exercise, meals, position, triggers, whoop, vomiting, infections, medicines, smoke or vaping, travel and family history.
- A normal chest radiograph does not exclude foreign body, bronchiectasis or aspiration. Red flags determine specialist CT, bronchoscopy, sweat test, ciliary, immune or swallow testing.
- Protracted bacterial bronchitis is an isolated chronic wet cough without alternative pointers that resolves after an appropriate 2-week antibiotic, usually co-amoxiclav. Obtain culture when feasible and review at the end.
- If wet cough fails to resolve after 2–4 weeks of appropriate treatment or recurs repeatedly, investigate bronchiectasis, foreign body, immune deficiency, CF and primary ciliary dyskinesia rather than repeating courses indefinitely.
- Asthma causes variable wheeze, breathlessness, triggers and objective airflow or inflammatory evidence. Isolated dry cough without these features should not receive escalating inhaled corticosteroid indefinitely.
- Post-infectious cough gradually improves after viral illness or pertussis. Antibiotics do not shorten a recovering viral cough; pertussis treatment mainly reduces transmission within its window.
- Somatic or tic cough is diagnosed positively after organic red flags are excluded; characteristic distractibility, suppressibility or absent sleep cough can support it. Avoid dismissive language.
- Do not empirically treat gastro-oesophageal reflux without compatible regurgitation, pain, dysphagia or aspiration features; acid suppression can cause harm.
- Remove smoke and vape exposure, check vaccination and provide a defined follow-up endpoint. Worsening breathing, haemoptysis, fever, weight loss or reduced intake needs earlier review.
Key red flags
Daily wet cough is abnormal and suggests endobronchial infection, bronchiectasis, aspiration or impaired clearance.
Sudden onset after choking, unilateral wheeze or recurrent same-lobe pneumonia requires foreign-body assessment even with normal radiography.
Clubbing, faltering growth, hypoxaemia, haemoptysis, recurrent pneumonia or abnormal chest signs requires paediatric respiratory referral.
Neonatal onset, feeding difficulty, cough with meals or recurrent aspiration suggests congenital, ciliary or swallowing disease.
TB contact, travel, weight loss, fever or night sweats requires prompt specialist and public-health investigation.
Progressive breathlessness, exercise limitation, cardiac signs, immune deficiency or abnormal spirometry prevents a nonspecific-cough label.
Investigation priorities
Identify focal collapse, infection, gross structural disease or cardiac enlargement.
Assess obstructive physiology and variable bronchodilator response.
Management branches
Cough persists daily beyond expected acute recovery.
- Identify physiological instability and red flags and establish wet versus dry quality.
- Take onset, trigger, feeding, infection and exposure history and examine growth, clubbing and focal signs.
- Obtain chest radiography and spirometry when feasible, then select rather than scatter further tests.