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Chronic cough in children
SYMPOSIUM: IMMUNITY AND INFECTION
Chronic cough in children
Epidemiology of cough Children are particularly prone to cough because they have an increased frequency of respiratory infection and increased cough receptor sensitivity. It is ‘normal’ for children to cough for 14e21 days following a lower respiratory tract infection. Prospective studies of acute cough following a viral infection in children have found that half last for more than 1 week, a quarter will persist for more than 2 weeks and approximately 5% for more than 4 weeks. Viral infections are very common in childhood and some normal children will have 10e12 infections per year. In contrast, adults typically have 2e4 viral respiratory infections per year. It follows that many children with apparently persistent cough are, in fact, suffering from sequential viral infections (see Box 1). Cough also occurs in the absence of recent infection or other obvious triggers. Otherwise healthy children who have been free from respiratory infections for a month will cough between 1 and 34 times per day (mean 11 times). A family or individual that is sensitized to cough may regard this normal, infrequent coughing as pathological. However, prolonged or nocturnal coughing are unusual and unresolved and persistent coughing can significantly impair quality of life. General population surveys have revealed that cough in the absence of apparent infection is common during childhood. Parents of children of 12e14 years of age reported cough in 28% of boys and 30% of girls. Cough for more than 3 weeks duration is also common and as an isolated symptom affects approximately 5% of 6e12 year old children.
Christopher Hine Francis Gilchrist Will Carroll
Abstract All children cough. Despite the ubiquity of this common symptom, it remains a concern for many parents and results in a significant number of health consultations. Nearly every child in the UK will present to their family doctor with cough as the predominant symptom in early childhood. Some children will present recurrently and the presence of persistent moist cough is a common cause for referral onwards. This article describes the scale of the problem and offers a framework for assessment of cough and describes the principles of treatment.
Keywords cough; cystic fibrosis; diagnosis; management; pertussis; protracted bacterial bronchitis
Introduction Cough is a common complaint of parents and a source of worry. Nearly all (92%) of children in the UK will have consulted a doctor with cough as the predominant symptom at least once by the time they are 5 years old. It is also a common source of referral to secondary and tertiary care clinics, particularly when the cough is persistent, intrusive or recurrent. Most children do not have a concerning underlying pathology but careful clinical assessment should be performed to establish those patients who require investigation and treatment. Coughing is a normal defensive process which allows the clearance of excess mucus or aspirated material. A cough begins with the stimulation of cough receptors. This results in a reflex deep inspiration followed by a very brief closure of the glottis accompanied by contraction of the respiratory muscles. Opening of the glottis results in transient maximal flow of air followed by lower expiratory flows and progressive dynamic compression of the airway as each cough continues at lower volumes. Airway debris and secretions are moved along by a combination of these airflows and ciliary activity. The sound of each cough is determined by a number of factors including the contents of the airway lumen (principally mucus), the airway calibre and the stiffness of the airway.
Describing cough As with most problems, a full history and complete examination are necessary embarking on investigation. In addition to usual questions about birth details, family history, growth and overall development there are four specific questions that help in reaching a diagnosis (See Figure 2).
Clinical case a baby with recurrent cough (Normal variant) 8 month old Alfie attends with his family due to concern regarding recurrent, irritating cough. The family describe him as “always coughing”, with a variety of descriptions as to how the cough sounds (sometimes wet, sometimes dry). They have attended their GP several times. Alfie has two older siblings at school and is thriving. A precise history reveals that Alfie’s symptoms are episodic, with exacerbations of cough accompanied by coryzal symptoms and episodic fever. The cough at the time of exacerbation is wet, with it steadily improving to a dry, occasional symptom. The cough slowly improves over time, eventually settling for a period, the pattern then starts again with the onset of another viral illness. (The family found it helpful to visualise the symptoms using a graph to represent the severity of the cough, Figure 1). The symptoms here describe a fit thriving infant with recurrent, episodic, viral infections associated with cough. The symptoms can feel relentless to families who may find it difficult to recall the last time their child was well. A careful history is required to identify the pattern of symptoms and identify the key periods of being asymptomatic.
Christopher Hine MBChB is a Specialist Registrar in Respiratory Paediatrics in the Department of Academic Paediatrics, University Hospitals of the North Midlands, Stoke-on-Trent, UK. Francis Gilchrist PhD is a Senior Lecturer in Respiratory Paediatrics in the Department of Academic Paediatrics, University Hospitals of the North Midlands, Stoke-on-Trent, UK and the Institute of Applied Clinical Sciences, Keele Univeristy, Keele, UK. Will Carroll MD is a Consultant Paediatrician in the Department of Academic Paediatrics, University Hospitals of the North Midlands, Stoke-on-Trent, UK and the Institute of Applied Clinical Sciences, Keele Univeristy, Keele, UK.
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Box 1
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Please cite this article in press as: Hine C, et al., Chronic cough in children, Paediatrics and Child Health (2017), http://dx.doi.org/10.1016/ j.paed.2017.02.001
SYMPOSIUM: IMMUNITY AND INFECTION
Figure 1 Difference in symptoms between viral cough and chronic cough.
When did it start? This is a helpful opening question in the consultation. Symptoms which are described from very early childhood suggest a congenital problem. Often parents will attribute coughing to a single event and reassurance may be necessary. For instance, it is common for parents to remain concerned for years after diagnosis of ‘pneumonia’ at any stage of childhood. Our experience is that this word is very frightening for parents and if it is used requires a careful explanation at the time.
Figure 3 Inspiratory chest X-ray of a child with suspected foreign body. No particular change is evident.
settle, particularly those associated with Bordetella pertussis (see Box 2) or Mycoplasma. Over this time period, the cough should be gradually settling in intensity and drying. It is acceptable to “watch and wait” a cough that is continuing beyond 4 weeks as long as there are no other worrying indicators for an urgent condition (e.g. foreign body). Children with continuous symptoms for more than 8 weeks have ‘chronic cough’.
How long has it gone on for? The definition of when a cough becomes “chronic” does not have a worldwide consensus. We follow the expert opinion offered in the British Thoracic Society recommendations for the assessment and management of cough in children to separate children into three groups (see further reading). Children with symptoms that last for less than 3 weeks are described as ‘acute cough’. This period allows time for a majority of coughs from simple infective causes to settle. Children who have an episode of coughing which lasts for 3e8 weeks are described as having ‘prolonged acute cough’. This interval covers the time that it takes from some coughs associated with acute respiratory tract infections to
Is it wet or dry? In assessing of cough it is helpful to obtain an accurate description of its nature and severity. Increasingly, we have found that parents often record coughing episodes using mobile devices and if the child will not or does not cough during a consultation, review of these can be helpful in determining the likely cause for
Figure 2 Assessment of cough in children.
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When does it occur? The timing of coughing episodes is particularly helpful in establishing the likely diagnosis. If episodes are triggered by feeding, then further evaluation of the child’s swallow is important. Gastroesophageal reflux should also be considered as this is a common cause of chronic cough in all ages. A child with significant, troublesome reflux may find coughing episodes are associated with lying flat and effortless vomiting but it is uncommon to be presented with classic symptoms. Disappearance of symptoms during sleep is virtually diagnostic of habit or psychogenic cough (Box 3).
Examination Unless they have already done so, always ask the child to cough. Younger children rarely cough at request. Therefore it is important to remain vigilant during the consultation. Sometimes the sound of a cough in itself is diagnostic and there are several useful adjectives that can be used to describe cough. A cough may be dry or wet (productive or moist). A low pitched, barking cough occurs in croup. A very similar cough occurs in children with narrow and slightly floppy airways. A marked prolonged expiratory phase with coughing suggests that there is small to moderate airways obstruction. Sometimes there is audible wheeze accompanying this. Both of these findings are suggestive of asthma. Apart from the cough physical examination is otherwise often completely normal but this does not exclude important pathology. It is vital to always plot the growth parameters. Any child with faltering growth requires thorough investigation and as a minimum those with persistent moist cough should have a basic immune function screen and sweat test. Other important specific physical signs should be sought. An inflamed nose with or without markers of allergy should make you think of either postnasal drip or asthma.
Figure 4 Expiratory chest X-ray of the same child. Asymmetrical hyperinflation of the right lung in expiration suggests a foreign body lodged in the right main bronchus.
any cough. Parents can have difficulty describing the way the cough sounds or accurately describing the severity, but the description of a wet or moist cough is one of the more reliably reported factors. The term of a “wet” or “moist” cough describes the sound of secretions being shifted during the cough expulsion. It does not describe the anatomical location of the secretions, their nature, or whether they are pathological or not. In children with ongoing symptoms for more than 3 months, a wet cough has been shown to be the most sensitive pointer to an underlying pathology. A daily moist cough is a sensitive pointer to a ‘specific cough’, i.e. there is likely to be an identifiable underlying diagnosis.
A teenager with a troublesome dry cough (psychogenic cough)
Whooping cough
Annabel is a 16 year old girl who presents with her mother after 6 weeks of concern regarding a persistent cough which began with a mild viral illness. The cough is dry and irritating to the family as she will cough frequently during the evening while watching TV. Teachers at school have commented on the symptom as it is disrupting her studies and ‘bothering’ classmates. The cough results in a honking noise and seems to occur more frequently in the presence of family or at school. It can be replicated on demand and Annabel has a completely normal respiratory examination. The honking (like a Canadian goose) and explosive nature of this cough (loud and intrusive) is typical of a psychogenic cough and is a common cause of the unexplained dry cough in adolescents. There is undoubtedly overlap between this condition and habit cough, which may be less intrusive and results in recurrent ‘throat-clearing’ or ‘tic cough’ in which there may be associated motor stereotypies. The cough can increase with attention on the symptom and decreases with involvement and concentration in some activity. Management is with careful explanation of the symptom without the allocation of blame or suggestion that it is invented. Physiotherapy guided breathing exercises or hypnotherapy can be helpful.
Paul is a 12 year old boy with a 4 week history of relentless paroxysmal cough and occasional post-tussive vomiting. Paul is described as going red in the face during coughing fits. This episode started with coryzal symptoms. He was previously fit and well and is fully immunised. He does not report a whoop at the end of the cough and has a normal examination. The rest of his family are well. Paul’s symptoms are compatible with B. pertussis infection or whooping cough. The characteristic “whoop” is not invariably present, particularly in the very young. The cough can persist for 3 months, but more typically lasts 2e6 weeks. The most at risk group are younger unvaccinated infants. Older children with pertussis who have been vaccinated usually have a less severe illness. Diagnostic confirmation can be difficult, with the best chance of a positive culture result on nasopharyngeal swab being within the first 3 weeks of the illness. Pertussis serology can be helpful in confirming a diagnosis but rarely affects treatment. Pertussis is highly contagious. Early treatment with a macrolide (azithromycin or clarithromycin), in the first 2 weeks of the illness will reduce transmission but does little to alleviate symptoms. Box 2
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Box 3
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likely to have symptoms that spontaneously resolve. The optimal timing of any imaging should be carefully considered; often a chest X-ray taken during an acute illness (an exacerbation of cough, coryzal, temperature) will show changes consistent with infection and it is helpful to wait at least 6 weeks from a significant infective episode if possible so the patient is in a “baseline” situation.
Check for clubbing. Its presence should always trigger further investigation. Looks for Harrison’s sulci or chest wall deformities. If present these suggest that symptoms are likely to have occurred over a prolonged period and there is an associated longstanding increase in the work of breathing. It is helpful to carefully check the respiratory rate and document the waking oxygen saturations.
Investigations Assessment of the basic immunophenotype We recommend that children with chronic wet cough should have a basic assessment of their immunophenotype (Box 5). This includes as a minimum a full blood count, immunoglobulins (IgA, IgG, IgM and IgE) and functional antibodies. Interpretation of functional antibody results can be a little complicated as it is common for normal children to have slightly low responses to some of the pneumococcal serotypes. However, we still find this a relatively useful test and perform it in our clinics. If there are other diagnostic markers of immunodeficiency such as faltering growth or severe eczema then further more detailed assessment is required and can include neutrophil burst testing and lymphocyte subsets.
Lung function We recommend that lung function tests are performed on all children presenting with chronic cough who are able to do them. Most children over 5 years of age can perform adequate spirometry and examination of the shape of the flow-volume loops helps to identify if there is restriction or obstruction. The presence of salbutamol reversibility (an increase of 12% of FEV1) confirms a diagnosis of asthma (see Box 4). The presence of an elevated breath nitric oxide (FeNO) is less specific but may be helpful in clinical practice (see further reading). Cough swab or sputum culture Most children with chronic cough do not expectorate sputum. However, if they do it is helpful to attempt sputum culture. It can be helpful to attempt an induced sputum sample using hypertonic saline with assistance from respiratory physiotherapists. The diagnostic yield from induced sputum is close to that of broncho-alveolar lavage samples in children with cystic fibrosis. For those who are not able to expectorate, then a cough swab may provide useful additional information. Certainly, it can help guide antibiotic therapy. However, both cough swabs and sputum samples have a lower diagnostic yield than samples obtained at flexible bronchoscopy.
Sweat test Although most children born in the UK today have cystic fibrosis diagnosed as a result of newborn screening testing, a small but significant number of children with cystic fibrosis are still diagnosed late. Screening is more likely to miss children with pancreatic sufficient cystic fibrosis and they can (and do) present late with cough and chest X-ray changes. It is therefore still a useful test to undertake when confronted with a child with a persistent moist cough (Box 6). Flexible bronchoscopy Where it is available, flexible bronchoscopy is a very helpful investigation. It enables direct microbiological sampling of each lobe of the lung, broncho-alveolar lavage (BAL). This is significantly more sensitive in determining the precise nature of any persistent endobronchial infection. There are a number of clear
Chest X-ray Any child with chronic wet cough should have a chest X-ray. Children with chronic cough and a normal chest X-ray are more
Cough and asthma John is a seven year old boy with symptoms of recurrent cough, worst at night, in cold weather and after exertion. There is no audible wheeze, the cough is dry, but he does get slightly breathless at times. He has eczema and is allergic to eggs. The family has a history of asthma and eczema. John’s symptoms clearly hint at a diagnosis of asthma. It is an extremely common condition, affecting 1 in 11 children in the UK and so should always be considered as a potential cause of respiratory complaints. Clues that would support a diagnosis of asthma can be found from a history including symptoms (including wheeze and chest tightness) from multiple triggers, a strong atopic background, and a previous response to anti-asthma medication. Asthma is challenging to diagnose in patients with isolated cough and the existence of ‘cough-variant asthma’ is disputed. Most patients who present this way will turn out not to have asthma. If the history and/ or spirometry support a potential diagnosis of asthma, a trial of antiasthma therapy (inhaled corticosteroid and/or leukotriene receptor antagonist) is often helpful. This will require careful monitoring with a definite period of time for treatment before review.
A child with common variable immunodeficiency Sophie is an 8 year old girl undergoing treatment for a left sided pneumonia. She has had three previous documented episodes of pneumonia in different anatomical locations along with a history of recurrent ear infections (for which grommets were inserted), and difficult to manage diarrhoea. Her immunoglobulins revealed low IgG and borderline low IgA levels. Immunodeficiency is rare, but the respiratory tract is the organ system most commonly involved in immunodeficiency disorders and there is often a delay of years between onset of symptoms and diagnosis. A low threshold of consideration is required as the history is not always forthcoming. Infections that are Severe, Persistent, Unusual or Recurrent (SPUR) should prompt clinical suspicion of an underlying immunodeficiency. Common variable immunodeficiency results in a relative lack of IgG production and typically presents in the 2nde4th decade of life with recurrent bacterial, viral, fungal and parasitic infections.
Box 4
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Box 5
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Please cite this article in press as: Hine C, et al., Chronic cough in children, Paediatrics and Child Health (2017), http://dx.doi.org/10.1016/ j.paed.2017.02.001
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A child with faltering growth and persistent wet cough
A 5 year old with a persistent wet cough
David is a 3 year old boy who is referred for assessment of a persistent wet cough. He is the third child of a travelling family and admissions have occurred at three different hospitals in the UK. He has had recurrent respiratory infections following on from an episode of bronchiolitis at 6 months. His weight is on the 0.4th centile and his length is on the 25th centile. His chest X-ray shows marked peribronchial thickening with areas of increased opacification at the right base. He is treated with oral amoxicillin-clavulanate for 2 weeks whilst a sweat test and baseline blood tests (full blood count, immunoglobulins, functional antibodies) are organized. His sweat chloride is 77 mol/L confirming a diagnosis of cystic fibrosis. It is more common, in our experience, to find that children who present late are often pancreatic sufficient and a significant proportion have missed newborn screening.
Harry is a five year old with a persistent wet cough which started four months ago. It has never completely resolved but tends to get worse with intercurrent illness. His parents describe him as ‘rattly’ all the time. He is well otherwise, with no other significant medical history and is growing and thriving. The family had noted that his cough got a little better following treatment with 5 days of amoxicillin, but quickly returned after cessation of the antibiotic. He has a basic immunophenotype and sweat test, which are both normal before a flexible bronchoscopy. The gross anatomy is normal but there are increased mucopurulent secretions. On culture a combination of Haemophilus influenzae and Moraxella catarrhalis are grown from different lobes. He is treated with a 6 week course of oral amoxicillinclavulanate and his cough completely resolves. Persistent bacterial bronchitis (PBB) is the presence of a wet cough for more than one month with resolution following treatment with antibiotic (with the absence of pointers suggestive of an alternative diagnosis). There may be a description of concurrent wheeze or of “rattly breathing” due to secretions within the large airways. Care should be taken to exclude other causes, and the diagnosis of PBB should only be given when these are carefully considered and excluded. The pattern of the cough may be that of a constant wet cough, or one that occasionally remits temporarily after a short course of oral antibiotic or during summer months. A sputum culture or a cough swab can be helpful in identifying an organism but this can be challenging. The only reliable way to make the diagnosis unequivocally is to undertake bronchoscopy examination. Often the diagnosis is confirmed following a successful trial of oral antibiotics. Treatments are targeted at the most common organisms (H. influenzae and Streptococcus pneumoniae). Most children’s symptoms resolve after a long course of oral antibiotics. The optimal length of antibiotic course is not known (but is between 2 and 6 weeks).
Box 6
indications including: suspicion of airway abnormality, persistent localised changes on chest X-ray, evaluation of aspiration lung disease. Whilst flexible bronchoscopy requires general anaesthesia, it is helpful in establishing the presence of large airway malacia, congenital abnormalities and the extent of any secretions or large airway inflammation. BAL data are useful in identifying pathogens involved in infective lung disease and can guide antibiotic therapy (see Box 7). Very occasionally an unexpected finding is an intraluminal foreign body (see Box 8). CT scan of the thorax CT scan of the thorax is the current gold standard for looking at small airway structure. Modern scanners can give detailed images with a very short scan time and often scans can be performed without sedation. The dose of radiation involved is not insignificant (between 20 and 150 times that of a chest X-ray depending upon the age and protocol used) and so careful consideration is required when choosing who should have imaging. We reserve CT scans for children whose cough persists despite treatment and when other investigations have been completed. Studies in tertiary care show that almost half of children undergoing CT scans of the chest with persistent moist cough of more than 6 months duration have abnormalities. Unsurprisingly, the chance of demonstrating an abnormality on CT is higher if the baseline chest X-ray is abnormal but normal baseline chest X-ray does not exclude bronchiectasis. Moreover, CT is excellent for demonstrating more subtle parenchymal changes.
Box 7
A child with inhaled foreign body Noah is 4 years old and presents acutely with his third episode of sudden onset wheezing and high temperatures within a period of 2 months. He has right upper lobe consolidation on this occasion, although previously he has had right lower lobe and left lower lobe changes. In between these episodes he has a persistent moist cough but is thriving. There is no history of acute choking or coughing although his parents recall the onset being quite sudden. Noah has decreased air entry on the right side with unilateral wheeze. An inhaled foreign body is an important differential for any child with cough with an abrupt onset. Whilst an episode of choking or gagging is often reported these symptoms are not recalled in up to half of cases. Foreign bodies are more common in younger children, particularly those with slightly older siblings who may have, unwitnessed, supplied the offending foreign body. There may be focal signs on examination including wheeze or crepitations. Initial investigation can include inspiratory and expiratory chest X-rays (Figures 3 and 4). If inhalation of a foreign body is suspected, the patient should be investigated urgently with a rigid bronchoscopy while allowing the child to remain comfortable and in an upright position.
Videofluoroscopy Children with neurodisability are at increased risk of swallowing incoordination and recurrent aspiration. This commonly but not invariably occurs in combination with gastroesophageal reflux. Obtaining a high quality study requires input from an experienced paediatric radiologist and speech and language therapists (see Box 9). Ciliary studies Ciliary dyskinesias are probably underdiagnosed. In many instances a child with ciliary dyskinesia has very early onset nasal
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Box 8
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respectively. Although there is little high quality evidence to guide the precise therapy, our practice is to use a two week course of amoxicillin-clavulanate with careful review following completion. Should there be improvement of symptoms, follow up is required to ensure genuine long-term resolution. Persistent symptoms require further investigation. Following investigation some children do not have a specific diagnosis but continue to have significant symptoms. In this group, we have found that the judicious use of prophylactic azithromycin (10 mg/kg three times a week) can significantly reduce their symptom burden. Many younger children eventually outgrow their need for antibiotics and we recommend regular trials off therapy, particularly in the summer months. The evidence in this area is lacking and requires research.
Case of infant with structural upper airway problem Jack is 5 months old and has presented with recurrent episodes of ‘difficulty breathing’. He is a generally well, term baby who has had several admissions with bronchiolitis over the first few months of life. He has been admitted to hospital twice, tending to improve when on oxygen and nasogastric tube feeds. His mother recalls that he has always struggled to feed from the bottle, tending to cough and choke. On chest X-ray, there are generally diffuse changes bilaterally. Investigation with videofluoroscopy and examination of the upper airway demonstrates a laryngeal cleft. Symptoms from birth suggest a congenital anomaly and when associated with difficulty feeding commoner diagnoses include laryngeal cleft or tracheo-oesophageal fistula. The likelihood of airway abnormalities increases with the presence of other, known anomalies including cardiac and genito-urinary malformations. The examination should include a thorough system wide check for dysmorphic features or anomalies of any sort.
Inhaled corticosteroids (ICS) In the presence of an isolated dry cough without further clues as to the diagnosis, consideration should be given to asthma. Our combined experience suggests that even children with predominantly wet cough at the outset often, in time, develop symptoms more suggestive of asthma in the longer term. As described above, asthma is very common and an approach to its assessment is described (Box 4). When undertaking a therapeutic trial of low-dose ICS, it is helpful to set a limit for the assessment period of 8e12 weeks. After this, the need for treatment is reviewed and stopped if it has not been helpful. It is helpful to perform lung function tests in children able to do this (pre and post therapy) and ensure parents carefully record any changes in symptoms. A proportion of apparently persistent coughs will spontaneously resolve and it is important not to attribute any change in symptoms to ICS unless there is relapse upon withdrawal.
Box 9
symptoms (nasal obstruction and purulent rhinorrhoea). Almost half of children with a ciliary dyskinesia have dextrocardia with situs inversus because cilia are responsible for lateralization during embryogenesis. Defective ciliary function leads to lateralization becoming a ‘random’ event. In children with dextrocardia, diagnosis is rarely a challenge but children with levocardia often present late and may have endured years of symptoms and many unsuccessful treatments. Definitive diagnosis requires ciliary biopsy or ciliary brushings to be examined by electron microscopy. In many cases this is done at a specialist centre. Exhaled nitric oxide (FeNO) tends to be low and nasal nitric oxide (nNO) levels are very low.
Anti-reflux treatment There is insufficient evidence to suggest that patients with wet or dry cough (without clues on assessment as to an underlying cause) should try anti-reflux treatment to manage their symptoms. Even those with occasional gastroesophageal reflux symptoms are unlikely to see benefit (especially in the very young).
Management of the persistent wet cough Respiratory paediatricians are often gently teased by colleagues for the apparent lack of variation in management regimens for children with recurrent respiratory symptoms. In clinical practice there are three main groups of treatment for chronic symptoms: antibiotics, steroids and anti-reflux treatments. These are augmented greatly by assistance from a large multi-disciplinary team including respiratory physiotherapists, dieticians, clinical nurse specialists and speech and language therapists. The approach to management does vary depending on the underlying cause and in the presence of a persistent wet cough efforts should be made to arrive at a specific diagnosis. There exist good quality guidance for a number of specific diagnoses including asthma, cystic fibrosis, immunodeficiency states and ciliary dyskinesias. In the presence of a generally well and thriving child, in the absence of specific pointers to a cause of the cough, there have been several treatments described as “trials of therapy”.
Conclusion Cough is a very common symptom and nearly all children present to a doctor with an acute episode of cough in early childhood. A small, but significant minority of children have persistent, recurrent or troublesome symptoms. It is helpful in clinical practice to determine the precise nature and pattern of symptoms. When cough is persistent and wet then an underlying diagnosis should be sought and all children should have, at the very least, a chest X-ray, baseline blood tests and a sweat test.A FURTHER READING 1 Shields MD, Bush A, Everard ML, McKenzie S, Primhak R. Recommendations for the assessment and management of cough in children. Thorax 2008; 63: 1e15. 2 Munyard P, Bush A. How much coughing is normal? Arch Dis Child 1996; 74: 531e4. 3 Gilchrist FJ, Carroll WD. Assessing chronic cough in children. Paediatr Child Health 2016; 26: 273e5.
Antibiotics In children with prolonged wet cough, the most likely cause is persistent bacterial bronchitis with the most common pathogens being Haemophilus influenza and S. pneumoniae. Treatment targeted using broad spectrum antibiotics like amoxicillin-clavulanate for 2 or 6 weeks leads to resolution in approximately 50% or 70%
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Please cite this article in press as: Hine C, et al., Chronic cough in children, Paediatrics and Child Health (2017), http://dx.doi.org/10.1016/ j.paed.2017.02.001
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4 Faniran AO, Peat JK, Woolcock AJ. Persistent cough: is it asthma? Arch Dis Child 1998; 79: 411e4. 5 Ruggins N, Carroll W. Managing childhood asthma: clinical experience with the measurement of fractional exhaled nitric oxide (FeNO). Paediatr Child Health 2014; 24: 260e3. 6 Hay AD, Heron J, Ness A, ALSPAC Study Team. The prevalence of symptoms and consultations in pre-school children in the Avon Longitudinal Study of Parents and Children (ALSPAC): a prospective cohort study. Fam Pract 2005; 22: 367e74. 7 Hewlett EL, Edwards KM. Pertussis e not just for kids. NEJM 2005; 352: 1215e22. 8 Ojoo JC, Kastelik JA, Morice AH. A boy with disabling cough. Lancet 2003; 361: 674. 9 Bye MR. Use of a peak flow meter for positive feedback in psychogenic cough. Pediatrics 2000; 106: 852e3.
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10 Wurzel DF, Marchant JM, Yerkovich ST, et al. Prospective characterization of protracted bacterial bronchitis in children. Chest 2014; 145: 1271e8.
Practice points C
C
C C
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The differential diagnosis of cough is wide and it requires careful assessment Accurate description or video of coughing episodes is often diagnostic Chronic dry cough is often due to Pertussis infection Chronic wet cough usually has an underlying cause and requires investigation
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Please cite this article in press as: Hine C, et al., Chronic cough in children, Paediatrics and Child Health (2017), http://dx.doi.org/10.1016/ j.paed.2017.02.001
Chronic cough in children
Epidemiology of cough Children are particularly prone to cough because they have an increased frequency of respiratory infection and increased cough receptor sensitivity. It is ‘normal’ for children to cough for 14e21 days following a lower respiratory tract infection. Prospective studies of acute cough following a viral infection in children have found that half last for more than 1 week, a quarter will persist for more than 2 weeks and approximately 5% for more than 4 weeks. Viral infections are very common in childhood and some normal children will have 10e12 infections per year. In contrast, adults typically have 2e4 viral respiratory infections per year. It follows that many children with apparently persistent cough are, in fact, suffering from sequential viral infections (see Box 1). Cough also occurs in the absence of recent infection or other obvious triggers. Otherwise healthy children who have been free from respiratory infections for a month will cough between 1 and 34 times per day (mean 11 times). A family or individual that is sensitized to cough may regard this normal, infrequent coughing as pathological. However, prolonged or nocturnal coughing are unusual and unresolved and persistent coughing can significantly impair quality of life. General population surveys have revealed that cough in the absence of apparent infection is common during childhood. Parents of children of 12e14 years of age reported cough in 28% of boys and 30% of girls. Cough for more than 3 weeks duration is also common and as an isolated symptom affects approximately 5% of 6e12 year old children.
Christopher Hine Francis Gilchrist Will Carroll
Abstract All children cough. Despite the ubiquity of this common symptom, it remains a concern for many parents and results in a significant number of health consultations. Nearly every child in the UK will present to their family doctor with cough as the predominant symptom in early childhood. Some children will present recurrently and the presence of persistent moist cough is a common cause for referral onwards. This article describes the scale of the problem and offers a framework for assessment of cough and describes the principles of treatment.
Keywords cough; cystic fibrosis; diagnosis; management; pertussis; protracted bacterial bronchitis
Introduction Cough is a common complaint of parents and a source of worry. Nearly all (92%) of children in the UK will have consulted a doctor with cough as the predominant symptom at least once by the time they are 5 years old. It is also a common source of referral to secondary and tertiary care clinics, particularly when the cough is persistent, intrusive or recurrent. Most children do not have a concerning underlying pathology but careful clinical assessment should be performed to establish those patients who require investigation and treatment. Coughing is a normal defensive process which allows the clearance of excess mucus or aspirated material. A cough begins with the stimulation of cough receptors. This results in a reflex deep inspiration followed by a very brief closure of the glottis accompanied by contraction of the respiratory muscles. Opening of the glottis results in transient maximal flow of air followed by lower expiratory flows and progressive dynamic compression of the airway as each cough continues at lower volumes. Airway debris and secretions are moved along by a combination of these airflows and ciliary activity. The sound of each cough is determined by a number of factors including the contents of the airway lumen (principally mucus), the airway calibre and the stiffness of the airway.
Describing cough As with most problems, a full history and complete examination are necessary embarking on investigation. In addition to usual questions about birth details, family history, growth and overall development there are four specific questions that help in reaching a diagnosis (See Figure 2).
Clinical case a baby with recurrent cough (Normal variant) 8 month old Alfie attends with his family due to concern regarding recurrent, irritating cough. The family describe him as “always coughing”, with a variety of descriptions as to how the cough sounds (sometimes wet, sometimes dry). They have attended their GP several times. Alfie has two older siblings at school and is thriving. A precise history reveals that Alfie’s symptoms are episodic, with exacerbations of cough accompanied by coryzal symptoms and episodic fever. The cough at the time of exacerbation is wet, with it steadily improving to a dry, occasional symptom. The cough slowly improves over time, eventually settling for a period, the pattern then starts again with the onset of another viral illness. (The family found it helpful to visualise the symptoms using a graph to represent the severity of the cough, Figure 1). The symptoms here describe a fit thriving infant with recurrent, episodic, viral infections associated with cough. The symptoms can feel relentless to families who may find it difficult to recall the last time their child was well. A careful history is required to identify the pattern of symptoms and identify the key periods of being asymptomatic.
Christopher Hine MBChB is a Specialist Registrar in Respiratory Paediatrics in the Department of Academic Paediatrics, University Hospitals of the North Midlands, Stoke-on-Trent, UK. Francis Gilchrist PhD is a Senior Lecturer in Respiratory Paediatrics in the Department of Academic Paediatrics, University Hospitals of the North Midlands, Stoke-on-Trent, UK and the Institute of Applied Clinical Sciences, Keele Univeristy, Keele, UK. Will Carroll MD is a Consultant Paediatrician in the Department of Academic Paediatrics, University Hospitals of the North Midlands, Stoke-on-Trent, UK and the Institute of Applied Clinical Sciences, Keele Univeristy, Keele, UK.
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Figure 1 Difference in symptoms between viral cough and chronic cough.
When did it start? This is a helpful opening question in the consultation. Symptoms which are described from very early childhood suggest a congenital problem. Often parents will attribute coughing to a single event and reassurance may be necessary. For instance, it is common for parents to remain concerned for years after diagnosis of ‘pneumonia’ at any stage of childhood. Our experience is that this word is very frightening for parents and if it is used requires a careful explanation at the time.
Figure 3 Inspiratory chest X-ray of a child with suspected foreign body. No particular change is evident.
settle, particularly those associated with Bordetella pertussis (see Box 2) or Mycoplasma. Over this time period, the cough should be gradually settling in intensity and drying. It is acceptable to “watch and wait” a cough that is continuing beyond 4 weeks as long as there are no other worrying indicators for an urgent condition (e.g. foreign body). Children with continuous symptoms for more than 8 weeks have ‘chronic cough’.
How long has it gone on for? The definition of when a cough becomes “chronic” does not have a worldwide consensus. We follow the expert opinion offered in the British Thoracic Society recommendations for the assessment and management of cough in children to separate children into three groups (see further reading). Children with symptoms that last for less than 3 weeks are described as ‘acute cough’. This period allows time for a majority of coughs from simple infective causes to settle. Children who have an episode of coughing which lasts for 3e8 weeks are described as having ‘prolonged acute cough’. This interval covers the time that it takes from some coughs associated with acute respiratory tract infections to
Is it wet or dry? In assessing of cough it is helpful to obtain an accurate description of its nature and severity. Increasingly, we have found that parents often record coughing episodes using mobile devices and if the child will not or does not cough during a consultation, review of these can be helpful in determining the likely cause for
Figure 2 Assessment of cough in children.
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When does it occur? The timing of coughing episodes is particularly helpful in establishing the likely diagnosis. If episodes are triggered by feeding, then further evaluation of the child’s swallow is important. Gastroesophageal reflux should also be considered as this is a common cause of chronic cough in all ages. A child with significant, troublesome reflux may find coughing episodes are associated with lying flat and effortless vomiting but it is uncommon to be presented with classic symptoms. Disappearance of symptoms during sleep is virtually diagnostic of habit or psychogenic cough (Box 3).
Examination Unless they have already done so, always ask the child to cough. Younger children rarely cough at request. Therefore it is important to remain vigilant during the consultation. Sometimes the sound of a cough in itself is diagnostic and there are several useful adjectives that can be used to describe cough. A cough may be dry or wet (productive or moist). A low pitched, barking cough occurs in croup. A very similar cough occurs in children with narrow and slightly floppy airways. A marked prolonged expiratory phase with coughing suggests that there is small to moderate airways obstruction. Sometimes there is audible wheeze accompanying this. Both of these findings are suggestive of asthma. Apart from the cough physical examination is otherwise often completely normal but this does not exclude important pathology. It is vital to always plot the growth parameters. Any child with faltering growth requires thorough investigation and as a minimum those with persistent moist cough should have a basic immune function screen and sweat test. Other important specific physical signs should be sought. An inflamed nose with or without markers of allergy should make you think of either postnasal drip or asthma.
Figure 4 Expiratory chest X-ray of the same child. Asymmetrical hyperinflation of the right lung in expiration suggests a foreign body lodged in the right main bronchus.
any cough. Parents can have difficulty describing the way the cough sounds or accurately describing the severity, but the description of a wet or moist cough is one of the more reliably reported factors. The term of a “wet” or “moist” cough describes the sound of secretions being shifted during the cough expulsion. It does not describe the anatomical location of the secretions, their nature, or whether they are pathological or not. In children with ongoing symptoms for more than 3 months, a wet cough has been shown to be the most sensitive pointer to an underlying pathology. A daily moist cough is a sensitive pointer to a ‘specific cough’, i.e. there is likely to be an identifiable underlying diagnosis.
A teenager with a troublesome dry cough (psychogenic cough)
Whooping cough
Annabel is a 16 year old girl who presents with her mother after 6 weeks of concern regarding a persistent cough which began with a mild viral illness. The cough is dry and irritating to the family as she will cough frequently during the evening while watching TV. Teachers at school have commented on the symptom as it is disrupting her studies and ‘bothering’ classmates. The cough results in a honking noise and seems to occur more frequently in the presence of family or at school. It can be replicated on demand and Annabel has a completely normal respiratory examination. The honking (like a Canadian goose) and explosive nature of this cough (loud and intrusive) is typical of a psychogenic cough and is a common cause of the unexplained dry cough in adolescents. There is undoubtedly overlap between this condition and habit cough, which may be less intrusive and results in recurrent ‘throat-clearing’ or ‘tic cough’ in which there may be associated motor stereotypies. The cough can increase with attention on the symptom and decreases with involvement and concentration in some activity. Management is with careful explanation of the symptom without the allocation of blame or suggestion that it is invented. Physiotherapy guided breathing exercises or hypnotherapy can be helpful.
Paul is a 12 year old boy with a 4 week history of relentless paroxysmal cough and occasional post-tussive vomiting. Paul is described as going red in the face during coughing fits. This episode started with coryzal symptoms. He was previously fit and well and is fully immunised. He does not report a whoop at the end of the cough and has a normal examination. The rest of his family are well. Paul’s symptoms are compatible with B. pertussis infection or whooping cough. The characteristic “whoop” is not invariably present, particularly in the very young. The cough can persist for 3 months, but more typically lasts 2e6 weeks. The most at risk group are younger unvaccinated infants. Older children with pertussis who have been vaccinated usually have a less severe illness. Diagnostic confirmation can be difficult, with the best chance of a positive culture result on nasopharyngeal swab being within the first 3 weeks of the illness. Pertussis serology can be helpful in confirming a diagnosis but rarely affects treatment. Pertussis is highly contagious. Early treatment with a macrolide (azithromycin or clarithromycin), in the first 2 weeks of the illness will reduce transmission but does little to alleviate symptoms. Box 2
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likely to have symptoms that spontaneously resolve. The optimal timing of any imaging should be carefully considered; often a chest X-ray taken during an acute illness (an exacerbation of cough, coryzal, temperature) will show changes consistent with infection and it is helpful to wait at least 6 weeks from a significant infective episode if possible so the patient is in a “baseline” situation.
Check for clubbing. Its presence should always trigger further investigation. Looks for Harrison’s sulci or chest wall deformities. If present these suggest that symptoms are likely to have occurred over a prolonged period and there is an associated longstanding increase in the work of breathing. It is helpful to carefully check the respiratory rate and document the waking oxygen saturations.
Investigations Assessment of the basic immunophenotype We recommend that children with chronic wet cough should have a basic assessment of their immunophenotype (Box 5). This includes as a minimum a full blood count, immunoglobulins (IgA, IgG, IgM and IgE) and functional antibodies. Interpretation of functional antibody results can be a little complicated as it is common for normal children to have slightly low responses to some of the pneumococcal serotypes. However, we still find this a relatively useful test and perform it in our clinics. If there are other diagnostic markers of immunodeficiency such as faltering growth or severe eczema then further more detailed assessment is required and can include neutrophil burst testing and lymphocyte subsets.
Lung function We recommend that lung function tests are performed on all children presenting with chronic cough who are able to do them. Most children over 5 years of age can perform adequate spirometry and examination of the shape of the flow-volume loops helps to identify if there is restriction or obstruction. The presence of salbutamol reversibility (an increase of 12% of FEV1) confirms a diagnosis of asthma (see Box 4). The presence of an elevated breath nitric oxide (FeNO) is less specific but may be helpful in clinical practice (see further reading). Cough swab or sputum culture Most children with chronic cough do not expectorate sputum. However, if they do it is helpful to attempt sputum culture. It can be helpful to attempt an induced sputum sample using hypertonic saline with assistance from respiratory physiotherapists. The diagnostic yield from induced sputum is close to that of broncho-alveolar lavage samples in children with cystic fibrosis. For those who are not able to expectorate, then a cough swab may provide useful additional information. Certainly, it can help guide antibiotic therapy. However, both cough swabs and sputum samples have a lower diagnostic yield than samples obtained at flexible bronchoscopy.
Sweat test Although most children born in the UK today have cystic fibrosis diagnosed as a result of newborn screening testing, a small but significant number of children with cystic fibrosis are still diagnosed late. Screening is more likely to miss children with pancreatic sufficient cystic fibrosis and they can (and do) present late with cough and chest X-ray changes. It is therefore still a useful test to undertake when confronted with a child with a persistent moist cough (Box 6). Flexible bronchoscopy Where it is available, flexible bronchoscopy is a very helpful investigation. It enables direct microbiological sampling of each lobe of the lung, broncho-alveolar lavage (BAL). This is significantly more sensitive in determining the precise nature of any persistent endobronchial infection. There are a number of clear
Chest X-ray Any child with chronic wet cough should have a chest X-ray. Children with chronic cough and a normal chest X-ray are more
Cough and asthma John is a seven year old boy with symptoms of recurrent cough, worst at night, in cold weather and after exertion. There is no audible wheeze, the cough is dry, but he does get slightly breathless at times. He has eczema and is allergic to eggs. The family has a history of asthma and eczema. John’s symptoms clearly hint at a diagnosis of asthma. It is an extremely common condition, affecting 1 in 11 children in the UK and so should always be considered as a potential cause of respiratory complaints. Clues that would support a diagnosis of asthma can be found from a history including symptoms (including wheeze and chest tightness) from multiple triggers, a strong atopic background, and a previous response to anti-asthma medication. Asthma is challenging to diagnose in patients with isolated cough and the existence of ‘cough-variant asthma’ is disputed. Most patients who present this way will turn out not to have asthma. If the history and/ or spirometry support a potential diagnosis of asthma, a trial of antiasthma therapy (inhaled corticosteroid and/or leukotriene receptor antagonist) is often helpful. This will require careful monitoring with a definite period of time for treatment before review.
A child with common variable immunodeficiency Sophie is an 8 year old girl undergoing treatment for a left sided pneumonia. She has had three previous documented episodes of pneumonia in different anatomical locations along with a history of recurrent ear infections (for which grommets were inserted), and difficult to manage diarrhoea. Her immunoglobulins revealed low IgG and borderline low IgA levels. Immunodeficiency is rare, but the respiratory tract is the organ system most commonly involved in immunodeficiency disorders and there is often a delay of years between onset of symptoms and diagnosis. A low threshold of consideration is required as the history is not always forthcoming. Infections that are Severe, Persistent, Unusual or Recurrent (SPUR) should prompt clinical suspicion of an underlying immunodeficiency. Common variable immunodeficiency results in a relative lack of IgG production and typically presents in the 2nde4th decade of life with recurrent bacterial, viral, fungal and parasitic infections.
Box 4
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A child with faltering growth and persistent wet cough
A 5 year old with a persistent wet cough
David is a 3 year old boy who is referred for assessment of a persistent wet cough. He is the third child of a travelling family and admissions have occurred at three different hospitals in the UK. He has had recurrent respiratory infections following on from an episode of bronchiolitis at 6 months. His weight is on the 0.4th centile and his length is on the 25th centile. His chest X-ray shows marked peribronchial thickening with areas of increased opacification at the right base. He is treated with oral amoxicillin-clavulanate for 2 weeks whilst a sweat test and baseline blood tests (full blood count, immunoglobulins, functional antibodies) are organized. His sweat chloride is 77 mol/L confirming a diagnosis of cystic fibrosis. It is more common, in our experience, to find that children who present late are often pancreatic sufficient and a significant proportion have missed newborn screening.
Harry is a five year old with a persistent wet cough which started four months ago. It has never completely resolved but tends to get worse with intercurrent illness. His parents describe him as ‘rattly’ all the time. He is well otherwise, with no other significant medical history and is growing and thriving. The family had noted that his cough got a little better following treatment with 5 days of amoxicillin, but quickly returned after cessation of the antibiotic. He has a basic immunophenotype and sweat test, which are both normal before a flexible bronchoscopy. The gross anatomy is normal but there are increased mucopurulent secretions. On culture a combination of Haemophilus influenzae and Moraxella catarrhalis are grown from different lobes. He is treated with a 6 week course of oral amoxicillinclavulanate and his cough completely resolves. Persistent bacterial bronchitis (PBB) is the presence of a wet cough for more than one month with resolution following treatment with antibiotic (with the absence of pointers suggestive of an alternative diagnosis). There may be a description of concurrent wheeze or of “rattly breathing” due to secretions within the large airways. Care should be taken to exclude other causes, and the diagnosis of PBB should only be given when these are carefully considered and excluded. The pattern of the cough may be that of a constant wet cough, or one that occasionally remits temporarily after a short course of oral antibiotic or during summer months. A sputum culture or a cough swab can be helpful in identifying an organism but this can be challenging. The only reliable way to make the diagnosis unequivocally is to undertake bronchoscopy examination. Often the diagnosis is confirmed following a successful trial of oral antibiotics. Treatments are targeted at the most common organisms (H. influenzae and Streptococcus pneumoniae). Most children’s symptoms resolve after a long course of oral antibiotics. The optimal length of antibiotic course is not known (but is between 2 and 6 weeks).
Box 6
indications including: suspicion of airway abnormality, persistent localised changes on chest X-ray, evaluation of aspiration lung disease. Whilst flexible bronchoscopy requires general anaesthesia, it is helpful in establishing the presence of large airway malacia, congenital abnormalities and the extent of any secretions or large airway inflammation. BAL data are useful in identifying pathogens involved in infective lung disease and can guide antibiotic therapy (see Box 7). Very occasionally an unexpected finding is an intraluminal foreign body (see Box 8). CT scan of the thorax CT scan of the thorax is the current gold standard for looking at small airway structure. Modern scanners can give detailed images with a very short scan time and often scans can be performed without sedation. The dose of radiation involved is not insignificant (between 20 and 150 times that of a chest X-ray depending upon the age and protocol used) and so careful consideration is required when choosing who should have imaging. We reserve CT scans for children whose cough persists despite treatment and when other investigations have been completed. Studies in tertiary care show that almost half of children undergoing CT scans of the chest with persistent moist cough of more than 6 months duration have abnormalities. Unsurprisingly, the chance of demonstrating an abnormality on CT is higher if the baseline chest X-ray is abnormal but normal baseline chest X-ray does not exclude bronchiectasis. Moreover, CT is excellent for demonstrating more subtle parenchymal changes.
Box 7
A child with inhaled foreign body Noah is 4 years old and presents acutely with his third episode of sudden onset wheezing and high temperatures within a period of 2 months. He has right upper lobe consolidation on this occasion, although previously he has had right lower lobe and left lower lobe changes. In between these episodes he has a persistent moist cough but is thriving. There is no history of acute choking or coughing although his parents recall the onset being quite sudden. Noah has decreased air entry on the right side with unilateral wheeze. An inhaled foreign body is an important differential for any child with cough with an abrupt onset. Whilst an episode of choking or gagging is often reported these symptoms are not recalled in up to half of cases. Foreign bodies are more common in younger children, particularly those with slightly older siblings who may have, unwitnessed, supplied the offending foreign body. There may be focal signs on examination including wheeze or crepitations. Initial investigation can include inspiratory and expiratory chest X-rays (Figures 3 and 4). If inhalation of a foreign body is suspected, the patient should be investigated urgently with a rigid bronchoscopy while allowing the child to remain comfortable and in an upright position.
Videofluoroscopy Children with neurodisability are at increased risk of swallowing incoordination and recurrent aspiration. This commonly but not invariably occurs in combination with gastroesophageal reflux. Obtaining a high quality study requires input from an experienced paediatric radiologist and speech and language therapists (see Box 9). Ciliary studies Ciliary dyskinesias are probably underdiagnosed. In many instances a child with ciliary dyskinesia has very early onset nasal
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respectively. Although there is little high quality evidence to guide the precise therapy, our practice is to use a two week course of amoxicillin-clavulanate with careful review following completion. Should there be improvement of symptoms, follow up is required to ensure genuine long-term resolution. Persistent symptoms require further investigation. Following investigation some children do not have a specific diagnosis but continue to have significant symptoms. In this group, we have found that the judicious use of prophylactic azithromycin (10 mg/kg three times a week) can significantly reduce their symptom burden. Many younger children eventually outgrow their need for antibiotics and we recommend regular trials off therapy, particularly in the summer months. The evidence in this area is lacking and requires research.
Case of infant with structural upper airway problem Jack is 5 months old and has presented with recurrent episodes of ‘difficulty breathing’. He is a generally well, term baby who has had several admissions with bronchiolitis over the first few months of life. He has been admitted to hospital twice, tending to improve when on oxygen and nasogastric tube feeds. His mother recalls that he has always struggled to feed from the bottle, tending to cough and choke. On chest X-ray, there are generally diffuse changes bilaterally. Investigation with videofluoroscopy and examination of the upper airway demonstrates a laryngeal cleft. Symptoms from birth suggest a congenital anomaly and when associated with difficulty feeding commoner diagnoses include laryngeal cleft or tracheo-oesophageal fistula. The likelihood of airway abnormalities increases with the presence of other, known anomalies including cardiac and genito-urinary malformations. The examination should include a thorough system wide check for dysmorphic features or anomalies of any sort.
Inhaled corticosteroids (ICS) In the presence of an isolated dry cough without further clues as to the diagnosis, consideration should be given to asthma. Our combined experience suggests that even children with predominantly wet cough at the outset often, in time, develop symptoms more suggestive of asthma in the longer term. As described above, asthma is very common and an approach to its assessment is described (Box 4). When undertaking a therapeutic trial of low-dose ICS, it is helpful to set a limit for the assessment period of 8e12 weeks. After this, the need for treatment is reviewed and stopped if it has not been helpful. It is helpful to perform lung function tests in children able to do this (pre and post therapy) and ensure parents carefully record any changes in symptoms. A proportion of apparently persistent coughs will spontaneously resolve and it is important not to attribute any change in symptoms to ICS unless there is relapse upon withdrawal.
Box 9
symptoms (nasal obstruction and purulent rhinorrhoea). Almost half of children with a ciliary dyskinesia have dextrocardia with situs inversus because cilia are responsible for lateralization during embryogenesis. Defective ciliary function leads to lateralization becoming a ‘random’ event. In children with dextrocardia, diagnosis is rarely a challenge but children with levocardia often present late and may have endured years of symptoms and many unsuccessful treatments. Definitive diagnosis requires ciliary biopsy or ciliary brushings to be examined by electron microscopy. In many cases this is done at a specialist centre. Exhaled nitric oxide (FeNO) tends to be low and nasal nitric oxide (nNO) levels are very low.
Anti-reflux treatment There is insufficient evidence to suggest that patients with wet or dry cough (without clues on assessment as to an underlying cause) should try anti-reflux treatment to manage their symptoms. Even those with occasional gastroesophageal reflux symptoms are unlikely to see benefit (especially in the very young).
Management of the persistent wet cough Respiratory paediatricians are often gently teased by colleagues for the apparent lack of variation in management regimens for children with recurrent respiratory symptoms. In clinical practice there are three main groups of treatment for chronic symptoms: antibiotics, steroids and anti-reflux treatments. These are augmented greatly by assistance from a large multi-disciplinary team including respiratory physiotherapists, dieticians, clinical nurse specialists and speech and language therapists. The approach to management does vary depending on the underlying cause and in the presence of a persistent wet cough efforts should be made to arrive at a specific diagnosis. There exist good quality guidance for a number of specific diagnoses including asthma, cystic fibrosis, immunodeficiency states and ciliary dyskinesias. In the presence of a generally well and thriving child, in the absence of specific pointers to a cause of the cough, there have been several treatments described as “trials of therapy”.
Conclusion Cough is a very common symptom and nearly all children present to a doctor with an acute episode of cough in early childhood. A small, but significant minority of children have persistent, recurrent or troublesome symptoms. It is helpful in clinical practice to determine the precise nature and pattern of symptoms. When cough is persistent and wet then an underlying diagnosis should be sought and all children should have, at the very least, a chest X-ray, baseline blood tests and a sweat test.A FURTHER READING 1 Shields MD, Bush A, Everard ML, McKenzie S, Primhak R. Recommendations for the assessment and management of cough in children. Thorax 2008; 63: 1e15. 2 Munyard P, Bush A. How much coughing is normal? Arch Dis Child 1996; 74: 531e4. 3 Gilchrist FJ, Carroll WD. Assessing chronic cough in children. Paediatr Child Health 2016; 26: 273e5.
Antibiotics In children with prolonged wet cough, the most likely cause is persistent bacterial bronchitis with the most common pathogens being Haemophilus influenza and S. pneumoniae. Treatment targeted using broad spectrum antibiotics like amoxicillin-clavulanate for 2 or 6 weeks leads to resolution in approximately 50% or 70%
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Please cite this article in press as: Hine C, et al., Chronic cough in children, Paediatrics and Child Health (2017), http://dx.doi.org/10.1016/ j.paed.2017.02.001
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4 Faniran AO, Peat JK, Woolcock AJ. Persistent cough: is it asthma? Arch Dis Child 1998; 79: 411e4. 5 Ruggins N, Carroll W. Managing childhood asthma: clinical experience with the measurement of fractional exhaled nitric oxide (FeNO). Paediatr Child Health 2014; 24: 260e3. 6 Hay AD, Heron J, Ness A, ALSPAC Study Team. The prevalence of symptoms and consultations in pre-school children in the Avon Longitudinal Study of Parents and Children (ALSPAC): a prospective cohort study. Fam Pract 2005; 22: 367e74. 7 Hewlett EL, Edwards KM. Pertussis e not just for kids. NEJM 2005; 352: 1215e22. 8 Ojoo JC, Kastelik JA, Morice AH. A boy with disabling cough. Lancet 2003; 361: 674. 9 Bye MR. Use of a peak flow meter for positive feedback in psychogenic cough. Pediatrics 2000; 106: 852e3.
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10 Wurzel DF, Marchant JM, Yerkovich ST, et al. Prospective characterization of protracted bacterial bronchitis in children. Chest 2014; 145: 1271e8.
Practice points C
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The differential diagnosis of cough is wide and it requires careful assessment Accurate description or video of coughing episodes is often diagnostic Chronic dry cough is often due to Pertussis infection Chronic wet cough usually has an underlying cause and requires investigation
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Please cite this article in press as: Hine C, et al., Chronic cough in children, Paediatrics and Child Health (2017), http://dx.doi.org/10.1016/ j.paed.2017.02.001