Printed on: December 22nd, 2024

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Chronic cough in children

Chronic cough in children

The common causes of chronic cough in children are not the same as in adults. The British Thoracic Society defines a chronic cough as lasting 8 or more weeks, and acknowledges the grey area between 3 and 8w where a prolonged acute cough secondary to URTI or pertussis may still be present, but other diagnoses need to be considered. This BMJ review presents a logical approach (BMJ 2012;344:e1177).

Working out the most likely cause again depends on careful history and examination. In addition to the history for acute cough, specifically consider:

If there are no abnormal features in the history and examination, a period of watchful waiting with reassessment at 6–8w and appropriate safety netting is a reasonable option.

Very rarely! In the absence of wheeze or dyspnea, very few children with an isolated cough have asthma.

If wheeze is present, a child is atopic or there is a strong family history, then a trial of treatment may be indicated.

• Use an appropriate dose of inhaled corticosteroid through a spacer for 8–12w.
• Undertake PEFR diary monitoring if the child is capable, to look for objective improvement.
• After the trial, stop treatment to allow assessment of its effect.

A relationship between isolated cough and GORD has not been clearly established in children. In children with a diagnosis of reflux, a cough may be a feature.

A trial of treatment of reflux medication for otherwise well children with isolated cough is not recommended because there is no evidence they are effective.

In an otherwise completely well child with normal clinical examination and no suspicious features in the history, psychogenic cough may present as:

• A dry repetitive habit cough that persists for some time after an URTI.
• Child is otherwise well.
• Cough may be honking/bizarre in nature.
• Cough is often less prominent at night or when the child is distracted, and conversely can be particularly bad in the presence of parents or teachers.
• Often perpetuated by secondary gain, e.g. time off school, attention, cough sweets!

Over-the-counter cough medicines have been under increasing scrutiny both in the USA and UK over recent months. As doctors, most of us are relatively skeptical about their benefits, but generally have felt they were a harmless part of self-management. This editorial in the NEJM suggests otherwise! (NEJM 2009 357;23)

• Since 1985, there have been 6 RCTs comparing paediatric cough and cold preparations. None has shown a meaningful clinical difference between active drug and placebo.
• In the USA between 2004 and 2005, there were 1500 emergency room attendances where the cause of attendance was attributed to adverse effects of these medications, including:
  • Depressed consciousness associated with antitussives.
  • Hallucinations with antihistamines.
  • Cardiac arrhythmias with decongestants.
• The FDA identified 123 deaths related to the use of these products over a 20y period! Serious adverse events were usually associated with accidental overdose, interaction with other medication or allergy.
• It ruled that the marketing of these products does not fairly represent the balance of risk versus benefit.
• The result of this has been that drug companies in the USA have withdrawn OTC cough medicines for the under 2s, but continue to market them for older children.

This issue was reviewed in a BJGP editorial (BJGP 2008;58:757–758). It comments that there are 24 million episodes of OTC cough mixture use in the UK annually.

• A Cochrane review concluded that there was no good evidence for or against the effectiveness of OTC cough mixtures in acute cough (Cochrane 2008 CD0052B).
• Given the extent of use, adverse events are relatively rare BUT as there is no evidence of efficacy, any adverse event must be taken seriously.
• The MHRA in the UK has adopted a similar position to the FDA, and OTC cough medicines have been withdrawn from sale for the under-2s in the UK.

The BJGP editorial recommends that we use these consultations as an opportunity to educate about:

• The lack of proven efficacy of OTC preparations.
• The natural history of URTI and cough, as many parents expect symptoms to resolve far more quickly than is realistic.
• The use of simple linctuses such as glycerol, lemon or honey (though not for children aged <1y given the potential risk of botulism).

There are a number of 'red flags' for chronic cough in children that should prompt paediatric referral for further investigation:

• Neonatal onset of cough.
• A cough that persistently occurs with feeding.
• A chronic 'wet cough' lasting >4w.
• Neurodevelopmental problems.
• Failure to thrive.
• Recurrent pneumonia.
• Finger clubbing/chest wall deformity.
• Presence of comorbid conditions, e.g. heart disease, immunodeficiency.

It would be relatively unusual for us to request X-rays on children from primary care. This is more likely to form part of a secondary care assessment. Indications include:

• Uncertainty about diagnosis of pneumonia (diagnosis can be made clinically).
• Possibility of an inhaled foreign body (but normal CXR does not exclude).
• Clinical indicators of chronic respiratory disorder (clubbing, chest deformity, failure to thrive).
• Haemoptysis.
• An unusual clinical course, e.g. a cough that gets worse over 2–3w, suspicion of TB/malignancy.

Protracted bacterial bronchitis is one of the commonest causes of chronic ‘wet’ or productive cough lasting >4 weeks in children (Chest 2017;151(4):884). This will usually be a secondary care diagnosis, and should be considered in children with a >4w history of wet cough in the absence of any other specific pointers of chronic lung disease, e.g. cough on feeding, finger clubbing, significant CXR changes.

Historically, guidelines advocated protracted (6-week) courses of broad-spectrum antibiotics (BTS Guidelines on the recognition and management of cough in children 2007).

More recent guidance advises a 2-week course of antibiotic, extended to 4 weeks if the child is significantly improved but not cough-free after 2 weeks (Chest 2017;151(4):884). Chest physiotherapy may be advised.

In children who do not improve after 4 weeks, or who have recurrent episodes of protracted bacterial bronchitis, further investigations (CT scanning, immunology, sweat test) may be required to exclude chronic suppurative lung diseases such as bronchiectasis and cystic fibrosis.

Bronchiectasis as a cause of persistent respiratory symptoms in children has gained in prominence worldwide over the past decade. Though it is most common in low-income settings, it is useful to recognise the common presenting features. All children with suspected bronchiectasis will require referral to a paediatrician (Lancet 2018;392:866).

Chronic cough in childhood Lasting >4w. The causes are different from adults, and trials of treatment for GORD and postnasal drip (in the absence of a very clear history) are not recommended. Take a careful history, do an examination and plot a growth chart. An isolated cough without wheeze, dyspnoea or strong family history is unlikely to be asthma. If asthma is suspected, do a PEFR diary and offer an 8–12w trial of treatment. Failure to thrive, a 'wet cough' lasting >4w, a cough occurring with feeding and recurrent LRTI should prompt referral. If no abnormality is elicited in the history or examination, a period of watchful waiting for 6–8w with reassessment at the end is reasonable. OTC cough mixtures are ineffective for all and no longer available OTC for under-2s.