Table 2

Possible diagnosis and specific investigations to be considered

Specific pointers to diagnosisSuggested specific diagnosisInvestigations
Sudden onset coughInhaled foreign bodyBronchoscopy
Barking/brassy coughAirway malaciaBronchoscopy
Paroxysmal cough with classic inspiratory ‘whoop’Pertussis syndromeSerology for Bordetella, Mycoplasma, Chlamydia
Wheezing episodes/atopy/exertional dyspnoea/chest hyperinflation/pectus deformityAsthmaSpirometry (±bronchodilator responsiveness)
Rhinitis, allergic salute, throat clearingAllergic rhinitisAllergy testing; trial of treatment
Choking with feeds/chesty post feeds/neurodevelopmental abnormalityRecurrent aspirationCXR, barium swallow/pH/impedance studies, videofluoroscopy, bronchoscopy and BAL
Wet cough, poor growth, features of malabsorption, nasal polyps, purulent sputum, finger clubbingBronchiectasis (various causes, eg, cystic fibrosis, primary ciliary dyskinaesia)CXR, sweat test, genotyping, sputum culture, HRCT, nasal brushings, bronchoscopy
Recurrent infections, wet coughImmune deficiencyImmune function tests
Progressive cough, weight loss, fever, night sweats and haemoptysisTuberculosisCXR, Mantoux test, gastric aspirate for acid-fast bacilli, sputum culture
Dry cough and breathlessInterstitial lung diseaseCXR, spirometry, HRCT, lung biopsy
Abnormal cardiac examination, exertional dyspnoea, hypoxaemiaCardiac diseaseCXR, echocardiogram, cardiology referral
Honking, bizarre cough/cough disappears in sleepPsychogenic coughCXR, spirometry, avoid over-investigation which may reinforce problem
Mucopurulent drainage, chronic nasal obstruction, facial pain or pressureSinusitisImaging of the sinuses and/or an empirical trial of treatment
Medication history (ACE inhibitors/illicit drugs)Drug reactionChange/stop drug
Measure level
  • BAL, bronchoalveolar lavage; CXR, chest X-ray; HRCT, high-resolution CT.