Chronic cough: diagnostic approach

Overview & Definition

A parent brings a four-year-old to clinic exhausted, describing a cough that has run for six weeks, wakes the household, and has already earned two courses of salbutamol that did nothing. The temptation is to reach for the adult reflexes — asthma, reflux, post-nasal drip — but in a child that instinct is usually wrong. The first move is quieter and far more powerful: listen to the cough and ask whether it is wet or dry, and count how long it has truly lasted. [1]

Chronic cough is defined by duration, and the paediatric threshold is a daily cough persisting for more than four weeks. This is deliberately shorter than the eight-week adult definition, because a child who is still coughing at a month rarely has a lingering viral tail and more often has an identifiable, treatable cause. Between three and four weeks sits a grey zone of "prolonged acute cough," most of which is post-viral and settles, but the four-week mark is the point at which a systematic work-up becomes mandatory. [1] [2]

The reason the definition matters is that it forces a decision rather than a wait. An isolated dry cough in an otherwise well, thriving child with a normal examination and chest X-ray is usually non-specific and self-limiting, and the safest management is watchful review. A wet cough, by contrast, almost always signals airway secretions that need explaining, and it is the finding that should never be waved away as "just a virus." [2]

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1. [1]Chang AB, Landau LI, Van Asperen PP, et al Cough in children: definitions and clinical evaluation. Med J Aust, 2006.PMID 16618239
2. [2]Chang AB, Glomb WB Guidelines for evaluating chronic cough in pediatrics: ACCP evidence-based clinical practice guidelines. Chest, 2006.PMID 16428719
3. [3]Marchant JM, Masters IB, Taylor SM, et al Evaluation and outcome of young children with chronic cough. Chest, 2006.PMID 16685002
4. [4]Chang AB, Oppenheimer JJ, Weinberger MM, et al Management of Children With Chronic Wet Cough and Protracted Bacterial Bronchitis: CHEST Guideline and Expert Panel Report. Chest, 2017.PMID 28143696
5. [5]Chang AB, Oppenheimer JJ, Weinberger M, et al Use of Management Pathways or Algorithms in Children With Chronic Cough: CHEST Guideline and Expert Panel Report. Chest, 2017.PMID 28104362
6. [6]Kantar A, Chang AB, Shields MD, et al ERS statement on protracted bacterial bronchitis in children. Eur Respir J, 2017.PMID 28838975
7. [7]Marchant J, Masters IB, Champion A, et al Randomised controlled trial of amoxycillin clavulanate in children with chronic wet cough. Thorax, 2012.PMID 22628120
8. [8]Chang AB, Robertson CF, Van Asperen PP, et al A cough algorithm for chronic cough in children: a multicenter, randomized controlled study. Pediatrics, 2013.PMID 23610200
9. [9]O'Grady KF, Grimwood K, Torzillo PJ, et al. Effectiveness of a chronic cough management algorithm at the transitional stage from acute to chronic cough in children: a multicenter, nested, single-blind, randomised controlled trial. Lancet Child Adolesc Health, 2019.PMID 31635952
10. [10]Wark PA, Marchant JM Cough in Children and Adults: Diagnosis, Assessment and Management (CICADA). Summary of an updated position statement on chronic cough in Australia. Med J Aust, 2024.PMID 38600861
11. [11]Newcombe PA, Sheffield JK, Petsky HL, et al A child chronic cough-specific quality of life measure: development and validation. Thorax, 2016.PMID 26842959