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DR JO HARRISON,
consultant respiratory physician,
department of respiratory
medicine, Royal Children’s
Hospital, Melbourne, Victoria.
ACUTE RESPIRATORY ASSOCIATE PROFESSOR
infections in children
consultant respiratory physician,
department of respiratory
medicine, Royal Children’s
Hospital, Melbourne, Victoria.
Background Table 1: Classification of acute respiratory infections
Acute upper respiratory infections Acute lower respiratory infections
ACUTE respiratory infections are a by healthy children and result in sig- Nasopharyngitis Laryngotracheobronchitis (croup)*
major cause of morbidity and mortality nificant numbers of medical visits and
worldwide. They are responsible for hospital admissions, particularly in the
one in five deaths in children under the preschool age group. Otitis media Bronchiolitis
age of five years, with pneumonia the Based on the site of infection, acute
cause in 90% of these deaths. respiratory infections may be classified
Childhood mortality from respira- as acute upper or acute lower respira- Laryngotracheobronchitis (croup)* Influenza*
tory infections in developed countries tory infections (table 1). This article
such as Australia is fortunately rare, reviews the most common types of
but these diseases remain a signifi- acute respiratory infections, their clinical *Croup and influenza involve both upper and lower airways
cant cause of morbidity. They are the features, diagnoses and management. **Pertussis starts as a coryzal illness, but the main recognisable clinical feature of cough is
most common infections experienced cont’d next page lower airway in origin
HOW TO TREAT Acute respiratory infections in children
Epidemiology Active RSV Figure 1. Infant with acute viral bronchiolitis. Note hyperinflation, prominent perihilar bronchial
BRONCHIOLITIS is the • Clinical assessment.
most common cause of infection does not markings and some patchy airspace shadowing. Note: for infants with a clear clinical presentation,
a chest X-ray is not required for the diagnosis of bronchiolitis. Clinical features that
acute lower respiratory result in lasting should prompt urgent pae-
infection in children during diatric review of an infant
the first year of life. It is the
immunity, so with suspected bronchiolitis
most common cause of recurrent RSV are listed in table 2. The
admission to hospital in this stage of illness (disease tra-
age group, accounting for
infection is jectory) is an important con-
more than 50% of all such common. sideration in determining
admissions in Australia. The which patients require
peak incidence of bronchi- review, as babies in the early
olitis occurs in infants aged stages of infection are at risk
2-6 months, with more than of further deterioration,
80% of cases occurring in whereas those who have
babies under 12 months of been symptomatic for five
age. days or more are most likely
The most common infec- to be improving.
tious agent responsible for
bronchiolitis is respiratory Specialist management
syncitial virus (RSV), and Treatment of RSV infection
the epidemiology of bron- in hospitalised infants is
chiolitis is mainly deter- largely supportive and gen-
mined by the epidemiology erally includes supplemental
of this viral infection. RSV oxygen and fluid replace-
infections are most common ment either by nasogastric
in winter and spring in tem- tube or intravenously. Nasal
perate climates, with up to suction is often helpful, but
75% of all cases identified other therapies, including
between July and September physiotherapy, are not.
in temperate regions of Aus- Early introduction of con-
tralia. In tropical and sub- tinuous positive airway pres-
tropical climates, epidemics sure (CPAP) for infants with
tend to occur in the rainy severe respiratory distress
season. Table 2: Clinical Assessment and Parents or carers should be often obviates the need for
There is virtually no pro- features of severe diagnosis given information on how intubation and mechanical
tection to young infants bronchiolitis The diagnosis of bronchioli- to recognise signs of deterio- ventilation.
from transplacental antibod- tis is clinical, based on the ration in their infant and be
ies, or from breast milk. Fur- • Poor feeding (fluid intake typical symptoms and exam- strongly advised to bring RSV prophylaxis
<50% of normal in the
thermore, active RSV infec- ination findings described them back for reassessment Palivizumab is a human
preceding 24 hours, poor
tion does not result in lasting above. Although fever is if it occurs. recombinant monoclonal
immunity, so recurrent RSV common, the finding of a Additional therapies such RSV antibody that is admin-
infection is common and can • Lethargy high fever (temperatures as bronchodilators, systemic istered as a monthly injec-
occur within the same • Apnoea >40°C) is unusual and and inhaled corticosteroids, tion during the RSV season.
season. • Respiratory rate > 70 should prompt careful con- nebulised adrenaline or Although it does reduce hos-
Almost all children experi- breaths per minute sideration of alternative antibiotics have been well pitalisation and admission
ence at least one RSV infec- diagnoses. shown to have no role in the rates to ICU in high-risk
tion during the first two • Nasal flaring or grunting In hospital settings the treatment of the infant with groups (for example, former
years of life, although only • Severe chest wall clinical diagnosis is usually bronchiolitis. In some cases, preterm infants, those with
10% of those infected recession confirmed by identifying bronchodilators can exacer- chronic lung disease or
develop acute bronchiolitis. • Cyanosis RSV, or another respiratory bate ventilation/perfusion acyanotic congenital cardiac
Most babies with bronchi- virus, in a respiratory mismatch and make infants disease), it has not been
• Oxygen saturation <92%
olitis can be managed at sample (usually nasopharyn- more hypoxic. This is shown to reduce the need
home, with about 1% geal aspirate). Immunofluo- important to consider, as it for mechanical ventilation.
requiring admission to hos- by inducing cell fusion and rescent (IF) antibody meth- can be tempting to treat the Consequently, its efficacy
pital. the formation of syncytia. ods allow rapid wheeze with bronchodila- and cost-effectiveness have
Factors that make hospi- Ciliated epithelial cells are identification of the virus tors ‘in case’ the diagnosis been challenged and it is
tal admission more likely destroyed and there is necro- responsible and enable is asthma. only available for babies in
include young age (particu- sis of the bronchiole epithe- infants with the virus to be Children over 12 months the high-risk groups in their
larly babies under three lia, along with oedema of isolated, which is important may also have bronchiolitis first RSV season.
months of age), prematurity the bronchiole walls and for infection control. IF and not respond to bron-
(particularly gestation less increased secretion of mucus. results are available within chodilators, although by this Prognosis
than 32 weeks), congenital a few hours and this method age a trial of a bronchodila- The prognosis for most
cardiac disease and chronic Signs and symptoms has excellent specificity and tor, especially in an atopic babies who develop acute
lung disease. Indigenous chil- Bronchiolitis presents most good sensitivity. The pres- child or one with a family bronchiolitis in Australia is
dren in Australia are also frequently in infants aged 3- ence of the virus is then usu- history of asthma, is reason- very good and overall mor-
more likely to require admis- 6 months, with breathing ally confirmed by viral cul- able. However, we would tality rates are very low.
sion, with rates of hospitali- difficulties, cough (may be ture, but this result is not recommend a trial dose Fifty per cent of previously
sation almost eight times dry/irritating or moist), poor available for up to one (administered through a healthy infants with bron-
those of non-Indigenous chil- feeding and fever. In very week. spacer) be given first under chiolitis will be symptom
dren. young babies (typically those Chest X-rays are not usu- observation to assess free after 14 days.
Spread of RSV occurs via under 1-2 months), the only ally helpful for diagnosing response. About 10%, however,
large droplets transferred to symptom may be apnoea. bronchiolitis (they usually develop a post-bronchiolitic
the individuals’ hands, Examination findings demonstrate a range of find- When to refer syndrome with symptoms of
where the virus can survive include: ings from hyperinflation, A small number of babies cough and wheeze that per-
for up to one hour. The virus • Tachypnoea. atelectasis and patchy infil- with bronchiolitis will sist for several weeks and
is then transferred to the • Increased work of breath- trates) (see figure 1). The require admission to hospi- can recur intermittently for
eyes or nose, resulting in ing (intercostal and sub- main role is if a differential tal. In deciding which babies several years, usually in
infection. RSV can also sur- costal recession, tracheal diagnosis is suspected clini- require admission, several association with subsequent
vive on hard surfaces for as tug and sometimes expira- cally, for example, because factors are taken into con- viral infections.
long as 30 hours. The incu- tory grunting). of localised chest signs sideration, including: Most eventually recover
bation period of RSV is • Chest hyperinflation. (pneumonia) or a heart • Age. completely, so that by the
between three and eight • Widespread crackles murmur (cardiac disease). • Presence of underlying age of 13 years there is no
days. and/or wheeze heard on comorbidities such as con- increase in wheezing
auscultation. GP therapy genital heart disease. episodes. RSV bronchiolitis
Pathogenesis These symptoms are usu- Mild bronchiolitis can usu- • Premature birth or chronic in infancy is not a risk
RSV invades the epithelial ally preceded by an initial ally be managed at home lung disease. factor for asthma in adult-
cells of the respiratory tract coryzal phase lasting for 2-3 with appropriate advice and • Socioeconomic factors. hood.
and spreads from cell to cell days. reassurance to the parents. • Geographical and trans- cont’d page 30
28 | Australian Doctor | 8 May 2009 www.australiandoctor.com.au
HOW TO TREAT Acute respiratory infections in children
ACUTE bronchitis is a tussis, whereas Streptococ- and harsh but then loosens ing exposure to irritants,
common clinical syndrome in cus pneumoniae, non- and becomes productive. particularly tobacco smoke.
children, caused by inflamma- typeable Haemophilus Children younger than five Although prescribed fre-
tion of the trachea, bronchi influenzae and Moraxella years rarely expectorate, and quently, antitussives and
and bronchioles, usually in catarrhalis may be signifi- sputum may be seen in vom- expectorants are not useful.
association with a viral respi- cant pathogens in preschool- itus. Parents frequently note There is growing concern
ratory tract infection. Acute ers. a rattling sound in the chest. about side effects from anti-
bronchitis is rarely bacterial The cause of the cough in Examination findings are tussives in children under
in otherwise healthy children. acute bronchitis is multifac- frequently normal although two years and a recent
Symptoms of acute bronchi- torial but involves mucosal the pharynx may be injected. Cochrane review failed to
tis usually include cough that injury, epithelial damage and Auscultation typically reveals find any benefit in any age
produces phlegm and may be the release of inflammatory clear lung fields, although group.
associated with retrosternal cytokines as well as transient scattered crackles or wheez- Antibiotics do not relieve
pain during deep breathing or bronchial obstruction and ing can sometimes be heard. symptoms or improve the
coughing. Generally the clini- hyper-responsiveness in a Recurrent episodes of natural history of acute
cal course is self-limiting, with proportion of patients. acute or chronic bronchitis bronchitis in otherwise
complete healing and full are unusual and should healthy patients.
return to function typically Signs and symptoms prompt consideration of
seen within 10-14 days after Acute bronchitis usually alternative diagnoses such as When to refer
symptom onset. Acute bronchitis of acute bronchitis, with begins with symptoms simi- asthma or suppurative lung Children with acute bronchi-
bacteria implicated in fewer lar to those of the common disease (cystic fibrosis, tis rarely require referral to a
Epidemiology usually begins than 10% of cases. The cold, such as coryza, malaise, immunodeficiency, ciliary paediatrician unless they
The annual incidence of bron- with symptoms organism responsible is not chills, low-grade fever, sore dyskinesia). have complicating underly-
chitis in children in the devel- usually identified in clinical throat, and back and muscle ing disease. However, per-
oped world is 20-30%, with
similar to those practice, but when viruses pain. The initial watery nasal GP therapy sistence of symptoms for
an equal incidence in males of the common are identified they are usu- discharge becomes thicker The vast majority of children more than one month or
and females. Acute bronchitis cold. ally one of the common res- and discoloured after several with acute bronchitis can be recurrence of symptoms of
occurs most commonly in piratory viruses such as days and is accompanied by managed as outpatients productive cough should
children younger than two influenza A or B, parain- a cough. Purulent nasal dis- unless their illness is compli- prompt consideration of
years, with a second peak seen fluenza or RSV. charge is common with viral cated by severe underlying alternative diagnoses such as
in children aged 9-15 years. Bacteria that can cause respiratory pathogens and, disease. Treatment is asthma, suppurative lung
acute bronchitis in otherwise by itself, does not imply an directed at symptoms and disease or retained foreign
Pathogenesis healthy school-age children underlying bacterial infec- includes analgesics and body. These will usually
Respiratory viruses are by include Mycoplasma pneu- tion. antipyretics, ensuring ade- require referral to a paedia-
far the most common cause moniae and Bordetella per- The cough is initially dry quate fluid intake and avoid- trician for confirmation.
CROUP, also known as laryngotra- parent’s knee and keeping them calm cise limitation between episodes, refer-
cheobronchitis, is caused by a viral Table 3: Assessing clinical severity of a child with croup is very important. ral to a paediatric respiratory physi-
infection of the upper airway. This Corticosteroids are used to treat cian or ENT surgeon is warranted.
• Mild: barking cough, no or intermittent stridor, no chest retractions
infection results in a classic triad of upper airway obstruction by reduc-
hoarse voice, barking cough and inspi- • Moderate: persisting stridor at rest, some chest wall recession or tracheal ing airway oedema and inflammation. Emergency management
ratory stridor. The condition usually tug, child easily pacified and interested in surroundings They should be prescribed for all but Systemic corticosteroids are prescribed
affects children from six months to the mildest cases of croup. Recom- if this has not already been done. Chil-
six years of age. • Severe: persisting stridor at rest, marked tracheal tug and chest wall mended doses are oral prednisolone dren with more severe croup may
recession, lethargic or restless, pulsus paradoxis 1mg/kg, or dexamethasone 0.3mg/kg require treatment with nebulised
Epidemiology given either orally or intramuscularly. adrenaline (1mL 1% solution mixed
The annual incidence of croup The onset of action seems to be within with 3mL normal saline; or 1:1000
depends on the incidence of infection 1-2 hours. undiluted at a dose of 0.5mL/kg to a
with viruses that cause this condition, Table 4: Diagnosing croup There is no effect on the cough, and maximum of 4mL), which reduces
but peaks occur in autumn and single doses, repeated as necessary, laryngeal inflammation, thus improv-
spring. The peak incidence occurs in Differential diagnosis Key features should be prescribed (rather than a ing the child’s airway. In the circum-
children aged 1-2 years and is about Triad of barking cough, stridor, hoarse voice; six three-day course as recommended for stance of a child requiring adrenaline,
60 per 1000 child-years. For reasons Croup asthma). Doses are given at 24-hour the GP should call an ambulance for
months to six years
that are not clear, croup is rare in intervals and if more than three doses transfer to hospital.
babies under six months of age and Toxic (high temperature), drooling, muffled voice, are required the child should see a Nebulised adrenaline lasts for up
uncommon in children older than six Epiglottitis no cough, may be unimmunised for H influenzae paediatrician. Parents whose children to two hours, but rebound worsen-
years. type B develop recurrent croup should be ing of the airway narrowing can occur
encouraged to give a dose of cortico- and this must be borne in mind.
Retropharyngeal abscess Sore throat, fever, drooling, no cough
Pathogenesis steroid as soon as they can predict a Repeat doses of adrenaline should be
Croup is due to a viral URTI that Sudden onset, no fever, stridor and/or wheeze, viral URTI will develop into croup. given as needed. A small number of
causes generalised mucosal inflamma- Foreign body difficulty feeding/swallowing if foreign body is children with croup will require intu-
tion and oedema of the larynx, tra- oesophageal When to refer bation to maintain their airway.
chea and bronchi, followed by epithe- Croup can cause life-threatening Nebulised budesonide (one
lial necrosis and shedding. The key *Stridor at rest indicates airway narrowing of at least 70% (ie, 30% or less residual lumen) upper airway obstruction, and chil- 1mg/2mL nebule) can be used as an
area of airway narrowing is the sub- dren with more severe illness need to alternative to adrenaline, although
glottis, with airway obstruction at this suddenly during the night. Usually this ing looser in nature after the first few be managed in a centre with access its onset of action is not as rapid.
site responsible for stridor. is preceded by a 1-2-day history of days. to staff trained in the management of The main role for nebulised budes-
Laryngeal inflammation also results non-specific symptoms of a viral paediatric airways. onide is for parent-initiated therapy
in impaired vocal cord movement, URTI, such as rhinorrhoea, sore Assessment and diagnosis All children under 12 months in those rare circumstances when
leading to the characteristic cough. In throat and fever. Croup is a clinical diagnosis based on should be referred for a paediatric children have a history of frequent
addition, fibrinous exudate can some- Stridor may develop, which can be the symptoms and signs described assessment, in part so that alternative severe episodes and access to ambu-
times result in pseudomembrane for- associated with difficulty breathing. above. Although there are several clin- diagnoses can be excluded. Older chil- lance support is poor.
mation, which results in further com- In more severe cases the child may ical scoring systems these are only dren should also be referred if they:
promise of the airway. have evidence of respiratory distress, useful as research tools and a basic • Have tracheal, sternal or subcostal Prognosis
Several viruses have been implicated with tachypnoea, tracheal tug and classification (table 3), provides a sim- indrawing at rest. Overall most children with croup
in causing croup, but parainfluenza chest wall retractions. Auscultation pler guide to assessment and manage- • Look toxic. have a mild illness that can be man-
virus types 1 and 3 are responsible usually reveals a clear chest, although ment. • Appear dehydrated, cyanosed or aged at home, with fewer than 5%
for about 80% of cases. Influenza air entry may be reduced in more exhausted. requiring admission to hospital. Of
types A and B, RSV, adenovirus and severe cases. GP therapy Children with milder symptoms those admitted, only 1-2% need intu-
metapneumovirus are responsible for Symptoms tend to be worse at night Formerly a popular treatment, steam should also be referred if their family bation, with a mortality rate for intu-
most of the other cases. and may fluctuate in severity, typically inhalation is not useful in the man- circumstances make home care inap- bated children of about 0.5%. Fortu-
becoming more severe if the child agement of croup and carries the risk propriate or there is uncertainty about nately, complications are rare in
Signs and symptoms becomes upset. Croup typically lasts of scalds. Antibiotics also have no role the diagnosis (see table 4). children with croup although second-
Croup normally starts with the typical for 2-3 days, but the cough can persist in the treatment of croup. However, If patients with recurrent croup have ary bacterial infection can occur, lead-
barking cough, which often comes on for up to two weeks, typically becom- sitting the child upright on their residual symptoms of stridor or exer- ing to pneumonia or tracheitis.
30 | Australian Doctor | 8 May 2009 www.australiandoctor.com.au
INFLUENZA is a highly infec- Signs and symptoms choalveolar lavage fluid. When to refer
tious respiratory disease Uncomplicated influenza Rapid results are obtained Patients who look unwell or
caused by the influenza results in respiratory symp- by directly detecting viral anti- in whom the complications
viruses. Three subtypes cause toms including dry cough, sore gens from these samples using described above are suspected
disease in humans — influenza throat, rhinitis and otitis the technique of reverse-tran- should be referred to a paedia-
A, B and C — but only the media, accompanied by sys- scription PCR, which provides trician or emergency depart-
first two cause clinically sig- temic symptoms including a sensitive assay able to differ- ment with facilities to care for
nificant disease. Influenza fever, myalgia, headache, entiate influenza A and B from children. There should be a
infections are often more malaise, fatigue, nausea and other viruses. lower threshold for referral
severe than infections caused vomiting. These symptoms are among patients with complex
by other respiratory viruses typically of acute onset but can GP therapy underlying medical conditions.
and cause constitutional as be difficult to differentiate The main treatments for
well as respiratory symptoms. from other respiratory infec- influenza are symptomatic, in Influenza vaccination
tions such as RSV. particular, maintaining fluids This is really in the domain of
Epidemiology Influenza usually lasts for up and encouraging rest. Antibi- preventive therapy. For many
Outbreaks of influenza are to a week, although the cough otics have no role unless sec- years there has been a stan-
unpredictable and occur in dis- and malaise can persist for 2-3 ondary bacterial infection is dard recommendation for chil-
tinct patterns. Pandemics weeks in some individuals. suspected. In recent years dren with complex medical
occur every 30-40 years and Influenza virus may be respon- antiviral therapy with conditions to receive influenza
are due to the emergence of a sible for most of the respira- oseltamivir (Tamiflu) and vaccination (see The Aus-
novel virus. Pandemics typi- tory illness discussed in this zanamivir (Relenza) have tralian Immunisation Hand-
cally occur outside the usual replicates. New influenza viri- article — bronchiolitis, bron- become available. book 9th edition).
season and spread rapidly ons are then shed into the res- chitis, croup and pneumonia. The difficulty is picking However, otherwise healthy
throughout the world. They piratory secretions. Complications of influenza which children have influenza children can benefit too. A
typically have high attack rates During this process, inflam- can occur in patients with pre- as the cause for their symp- recent report from SA high-
in all age groups and result in matory cytokines are pro- existing respiratory disease, toms. lighted that there were more
high rates of mortality, even in duced, which are responsible but infection can also result in A recent Cochrane review hospitalisations from influenza
previously healthy young for the systemic symptoms of secondary bacterial pneumo- showed that oseltamivir in the <2-year age group than
adults. influenza. nia, cause febrile convulsions reduced the median duration in those over 65, and even in
Epidemics occur much more The pathogenesis and viru- and be associated with of illness by 26% (36 hours) in those over 85. After three
frequently, usually every 1-3 lence of the influenza virus encephalopathy, transverse healthy children with labora- deaths from influenza in 2007
years, and are associated with depend on host factors such myelitis, myocarditis and tory-confirmed influenza. in WA in previously healthy
lower excess mortality. They as immunocompetence, and myositis in previously healthy There were not enough children, routine vaccination
occur as a result of antigenic viral factors, including anti- children. data on ‘at-risk’ children (eg for children aged between six
drift of the viruses, a process genic variation, ability of viral chronic respiratory or cardiac months and five years has
that results in the emergence shedding to take place and Assessment and diagnosis causes) to make a recommen- been recommended in that
of new strains of virus caused restriction of the cytopathic The influenza virus may be dation although there is no state.
by mutations within the virus effect of the virus to allow con- isolated from cell culture and, reason why a similar biological Children can be immunised
antibody binding sites. tinued replication to take while this remains the gold response would not be antici- with influenza vaccine from
place. standard and is essential for pated. Commencement of six months of age. Children
Pathogenesis The incubation period for monitoring circulating strains, therapy within 48 hours of under nine years need two
Influenza is spread from influenza is usually 1-4 days. it is too slow to be useful as a symptom onset is required. doses at least one month apart
person to person via respira- Children can be infectious for bedside test. There is some evidence that the first time they receive the
tory droplets. The virus binds several days before their symp- Suitable samples include oseltamivir may be effective vaccine (single doses are
to respiratory epithelial cells, toms appear and can continue nasopharyngeal aspirates or for prophylaxis if a household required in subsequent years).
which are rich in receptors, to shed the virus for more than swabs, throat swabs, sputum contact has confirmed The principal contraindication
and enters the cell, where it 10 days. when available, or bron- influenza. is allergy to eggs.
WHOOPING cough is an acute res- Young infants do whooping cough are paroxysms of which include direct testing of pregnancy should have adult per-
piratory tract infection first described cough followed by an inspiratory nasopharyngeal swabs with nucleic tussis-containing vaccine. Women
in the 1500s. Most cases are caused not always have whoop and/or vomiting. These acid amplification testing (NAAT), already pregnant can be vaccinated
by Bordetella pertussis, with B para- the characteristic symptoms are usually preceded by a culture, PCR or direct immunofluo- immediately after delivery.
pertussis responsible for about 5% catarrhal phase lasting a week or two rescent assays. An additional finding
of cases. whoop and can that resembles the common cold, may be of a significant lymphocytosis Treatment
present with with coryza and a non-productive although this is non-specific. Serol- Antibiotics do not alter the clinical
Epidemiology cough. The paroxysmal phase lasts ogy (B pertussis-specific IgA) is often course of whooping cough but elim-
Whooping cough epidemics occur apnoea even for several weeks, usually reaching insensitive in the early stages of the inate B pertussis from the nasophar-
every 2-5 years. There are 20-40 mil- before the cough its peak of severity in the first two disease and particularly unreliable ynx, rendering patients non-infec-
lion cases of whooping cough annu- weeks before gradually improving from infants. tious. The most effective antibiotic is
ally worldwide, 90% of which occur
is recognised. over the next 6-12 weeks. clarithromycin 7.5mg/kg (up to a
in low-income countries and result Young infants do not always have GP management maximum of 500mg) twice daily for
in an estimated 200,000-300,000 the characteristic whoop and can Prevention seven days.
fatalities a year. present with apnoea even before the Vaccination remains the main pre- For patients unable to tolerate
Whooping cough is spread by res- cough is recognised. Infants with ventive measure for control of macrolides, trimethoprim-sulfa-
piratory droplets and is highly conta- pertussis may look well between spread of this disease. The recom- methoxazole is an alternative antibi-
gious. After exposure to an acute paroxysms, without chest signs. mended schedule for pertussis vac- otic, given for seven days. The dose
case, 70-100% of unvaccinated Petechial and/or subconjunctival cination is at two, four, and six is 20mg trimethoprim with 100mg
household contacts and 50-80% of haemorrages may be evidence of the months, and four years of age. sulfamethoxazole per dose, twice
unvaccinated school contacts will severity of the coughing paroxysms. Infants are not protected until they daily for children under six months
become infected. Infants under 12 Young infants are at greatest risk of have had three doses. An adult per- of age. This dose should be doubled
months are at highest risk of compli- complications including en- tussis booster vaccine (Boostrix) is for older children.
cations and death. cephalopathy, pneumonia and feed- given to adolescents who are in A person who has been coughing
ing problems. year 10 at secondary school. for more than 21 days is no longer
Pathogenesis Adults who have not been vacci- infectious, and antibiotic treatment
Humans are the sole reservoir for Assessment and diagnosis nated with pertussis-containing is not indicated.
B pertussis and B parapertussis. B Pertussis can be diagnosed clinically vaccine for more than 10 years Antibiotics should also be given
pertussis is a Gram-negative pleo- in any patient with an acute cough have waning immunity and may to household contacts if the house-
morphic bacillus that spreads via that has lasted for two weeks or contract pertussis and pass it on. hold includes an infant under 24
aerosolised droplets from coughing more and which does not have More than half of infants aged months of age or a child of any age
of infected individuals. B pertussis another explanation, especially if under one year admitted to hospi- who is not fully vaccinated. Antibi-
attaches to and damages ciliated res- there is also a history of paroxysms, tal with pertussis have an adult otics should also be given to a con-
piratory epithelium. whoop or post-tussive vomiting. family member with clinical or lab- tact who is a pregnant woman
Contact history is also helpful. oratory-proven pertussis. during the last month of her preg-
Signs and symptoms The clinical diagnosis can be con- Although not yet funded (but nancy.
The characteristic symptoms of firmed by specific diagnostic tests, licensed for use) adults planning a cont’d next page
www.australiandoctor.com.au 8 May 2009 | Australian Doctor | 31
HOW TO TREAT Acute respiratory infections in children
from previous page territories also have guidelines/legisla- tions such as apnoea, poor feeding, cardio-respiratory monitoring, fluid patients with underlying cardiac,
Exclusion from school or child care tive requirements relating to exclusion pneumonia or encephalopathy. support and continuous oxygen pulmonary, neuromuscular or neu-
Children with whooping cough must times for unimmunised children from Older children or adolescents (who therapy if there is hypoxia with rological disease are at high risk for
be excluded from school or child care school or childcare, so GPs are advised will not have been vaccinated for some coughing. complications of pertussis (pneu-
until five days after they start their to contact their local public health unit years) may simply present with a trou- Investigations such as nasopha- monia, seizures, encephalopathy,
course of antibiotics. The Australian for information regarding their own blesome cough and at times the dif- ryngeal PCR or culture are per- death).
Immunisation Handbook recom- state/territory requirements. ferential diagnosis is unclear. Pertussis formed but antibiotics are usually The cough may persist for three
mends that unimmunised close con- serology (pertussis-specific IgA) can prescribed if the clinical suspicion months (‘the 100-day cough’) and
tacts should be excluded from child- When to refer be helpful in these circumstances. of pertussis is high. recrudesce with any subsequent res-
care for 14 days from the date of last Infants under 12 months with pertussis piratory infection, although rarely
exposure or until five days after start- should be assessed by a paediatrician, Specialist management Prognosis enough to warrant readmission to
ing a course of antibiotics. States and as they are at highest risk of complica- Specialist management involves Infants born prematurely and hospital.
PNEUMONIA can be Figure 2B. The same four-year-old child after 36 hours of intravenous penicillin. He is more
Figure 2A. A chest X-ray of a four-year-old child who presented
defined as inflammation and with high fever, lethargy and cough. On examination there was tachypnoiec with high fever. The air entry on the right is further reduced and the percussion note is
consolidation of the lung reduced air entry in the right lower zone with bronchial breath stony dull. This suggests the pneumonia has become complicated by a pleural effusion or
parenchyma, caused by an sounds. The chest X-ray shows opacification in the right lower empyema. The chest X-ray now shows more extensive opacification with mediastinal shift to the
infectious organism. Most lobe with some air bronchograms. Note: the right heart border left and evidence of the effusion/empyema.
cases of pneumonia in chil- appears clear suggesting the infection is not in the middle lobe.
dren are community acquired
and occur in previously to the left,
healthy children. The diagno- suggesting
sis is clinical and does not large volume
require chest X-ray confirma- of pleural
Pneumonia is most common
in younger children, with an
annual incidence of 35-40
cases per 1000 children under More extensive
five years of age, which falls opacification
to seven cases per 1000 in which may be
adolescents aged 12-15 years.
space fluid or
The age of the child is more extensive
important in determining the pneumonia.
likely pathogen responsible.
In neonates, group B strepto-
coccus and Gram-negative
enteric bacteria are the most
Beyond the neonatal because the inflammatory may present with abdominal Blood cultures should be Macrolide antibiotics may be severe cases of pneumonia or
period, viruses are by far the process occurs predominantly pain, particularly if the infec- performed in children with used as first-line treatment in if the child is unable to
most commonly implicated within the alveoli (where tion involves the lower lobes. more severe disease who children over five years, as absorb oral antibiotics (eg,
pathogens in children during there are few cough recep- The pain can be quite severe require admission to hospital, mycoplasma infections due to vomiting).
the preschool years, with tors) in the early stages of this and is due to referred pain although these prove positive become more common in this The first-line IV antibiotic
RSV, parainfluenza, aden- infection. Cough then from the diaphragmatic in fewer than 10% of cases. age group. for an uncomplicated pneu-
ovirus, becomes more prominent as pleura. Older children may Nasopharyngeal aspirates An essential part of the monia should be benzylpeni-
rhinovirus, influenza and inflammation spreads and also complain of chest pain. are useful for diagnosing viral management of pneumonia in cillin 30mg/kg six-hourly
cytomegalovirus all potential debris accumulates in the air- infections, particularly in children in the community is (60mg/kg four-hourly if infec-
causes in this age group. ways. Assessment and diagnosis younger children who require the provision of information tion is severe, but referral in
In children over five years Respiratory rate can be Pneumonia can be diagnosed admission to hospital. to the child’s family to allow these circumstances is
of age, S pneumoniae is the hard to count in healthy rest- clinically in most cases, The presence of bacteria in them to manage fever, pre- advised). Chest physiotherapy
most common cause, with M less children, but tachypnoea although it is extremely diffi- these samples cannot be used vent dehydration and identify is not beneficial and has no
pneumoniae and Chlamydia is an important sign in pneu- cult to distinguish bacterial to make a diagnosis, as they signs of deterioration in the place in the management of
pneumoniae the next most monia, as it is associated both from viral causes on clinical are commonly found as com- child’s condition. pneumonia in children.
frequent causative organisms. with severity and with grounds. Routine chest X-ray mensals. In children with The development of respi-
increased likelihood of under- in children with uncompli- pneumonia complicated by When to refer ratory failure may necessitate
Pathogenesis lying consolidation. Chest cated lower respiratory tract parapneumonic effusion, If pulse oximetry is available, transfer to the intensive care
S pneumoniae is carried in recession may be an accom- infections is not necessary. A pleural fluid should be a key indication that the child unit for ventilatory support.
the nasopharynx in about panying clinical feature. chest X-ray is helpful if the obtained if possible. is likely to require admission Parapneumonic effusions
50% of healthy children Auscultation typically diagnosis is in doubt, or the This should be sent for bac- to hospital is hypoxaemia, may require surgical
without causing symptoms. reveals crackles and/or child does not respond to terial antigen detection as well that is, an oxygen saturation drainage.
Various factors can lead to bronchial breathing. therapy as expected, or com- as microscopy and culture. of <92%.
invasive disease, such as the Localised signs increase the plications (such as parapneu- Other indications include Prognosis
acquisition of a new serotype chance of the infection being monic effusion or empyema) GP therapy tachypnoea (respiratory rate Death from pneumonia is
or concomitant viral infection bacterial, while generalised are suspected. Other investi- It is difficult to differentiate >70 breaths/minute in infants rare in the developing world
such as influenza, which signs may be more typical of gations, including FBC and viral, mycoplasma and bac- less than 12 months or >50 and the vast majority of chil-
increases the attachment of viral or mycoplasma infec- acute-phase reactants, are also terial causes of pneumonia by breaths/minute in older chil- dren recover completely.
the streptococcus to the respi- tion. However, these are not unnecessary in most cases and clinical examination. Added dren) as well as poor feeding Most children with a S pneu-
ratory epithelium. particularly specific or sensi- do not help distinguish to this is concern regarding or evidence of dehydration, moniae infection respond
The organisms reach the tive findings. between viral and bacterial the increasing incidence of apnoea or grunting, or if the within 24 hours; failure to do
lower respiratory tract by The presence of wheeze sug- pathogens. antibiotic resistance. Thus, family is unable to provide so suggests more serious
haematogenous seeding, gests either a viral or, particu- Urine testing for the pres- young children presenting appropriate care. infection or development of
although inhalation of infec- larly in school-age children, a ence of antigens is another with mild symptoms of lower Patients should be reviewed complications such as parap-
tious particles may be impli- mycoplasma infection. The unhelpful test, as their pres- respiratory tract infection do regularly within the first 48 neumonic effusion/empyema.
cated. In the alveoli, the classic mycoplasma prodrome ence is not specific for pneu- not require antibiotics. hours of illness, as failure to Other complications can
organisms multiply and is high fever and headaches monia. However, culture of a In more severe cases, if improve, or deterioration, occur, such as lung abscess
spread from alveolus to alve- before the cough appears, but clean-catch sample of urine antibiotics are prescribed, within this time frame is an and metastatic infections,
olus via the pores of Kohn. almost any presentation could should be performed in a amoxycillin (10-25mg/kg indication for review by a including osteomyelitis and
also be mycoplasma. It is gen- febrile child if the infective eight-hourly) should be the paediatrician. septic arthritis.
Signs and symptoms erally stated that mycoplasma cause is unknown, to exclude first choice, as it is effective Children with no pre-exist-
Pneumonia frequently starts is more common in the the possibility of an underly- against the most common Specialist management ing conditions who follow a
with a high fever accompa- school-age group (compared ing UTI. pathogens, is well tolerated Oxygen is provided if the standard course with rapid
nied by tachypnoea. Cough with preschoolers/infants), Serology (IgM) for and cheap. child is hypoxic. Antibiotics resolution of symptoms do
is often absent initially, partic- although this assertion is being mycoplasma has little role in Alternatives to amoxycillin are given if this has not been not need a progress chest X-
ularly when the infection is questioned. the GP setting because of the include roxithromycin (2.5- done previously, and may be ray if one was taken initially.
due to S pneumoniae. This is Children with pneumonia delay in receiving results. 4mg/kg 12-hourly). administered intravenously in cont’d page 34
32 | Australian Doctor | 8 May 2009 www.australiandoctor.com.au
HOW TO TREAT Acute respiratory infections in children
review in four days was focal chest signs and a clini- warrant antibiotic treatment.
arranged. cally severe infection?
He returned in three days, No. The appropriate strat- We are currently seeing many
at which time he was still egy was employed — starting cases of pertussis in the school-
febrile and coughing. On with a simple antibiotic age population. Should we be
examination his temperature (amoxycillin) in this age group. offering antibiotic treatment to References
was 38.0°C, pulse 120 The development of focal signs classmates who have been in 1. Smith SM, Schroeder K,
beats/minute and respiratory would warrant a chest X-ray if close contact with a patient Fahey T. Over-the-counter
rate 40 breaths/minute. He the child was not improving. with pertussis? medications for acute cough
DR GED FOLEY in children and adults in
Mosman, NSW was once more found to have air. He had intercostal reces- Atypical organisms and viral Data on contact prophylaxis ambulatory settings.
scattered expiratory wheeze, sions and the focal signs at the infections may cause localised are scarce, and defining close Cochrane Database of
Case study although now he had some right base were more marked. disease but I would be covering contact can be problematic. Systematic Reviews 2008,
JS, 18 months, presented with focal signs at the right mid- He was referred to the emer- for bacterial infection if signs The principles as outlined in Issue 1. Art. No.:
a history of an URTI four zone and base, with localised gency department. were localised. the ninth immunisation hand- 10.1002/14651858.CD0018
weeks before, followed by an inspiratory crackles and JS was an inpatient for only book are to protect young chil- 31.pub3.
intermittent cough. Over the slightly reduced air entry. two days and was treated with Previous studies have suggested dren (<24 months) who have 2. Matheson NJ, Harnden A,
preceding two days the cough The possibility of an atypi- oxygen and roxithromycin. that young children with puru- not been immunised com- Perera R, Sheikh A,
had become worse and was cal infection was considered Subsequent sero-logy indicated lent rhinorrhoea, fever and a pletely (this would include all Symmonds-Abrahams M.
Neuraminidase inhibitors for
associated with fever, malaise, and erythromycin was added. infection with Chlamydia chesty cough have focal areas infants under six months, none preventing and treating
rapid breathing and poor He was also given inhaled pneumoniae. His cough per- of pulmonary infection that are of whom have had three doses influenza in children.
appetite. There was no rele- salbutamol via a spacing sisted for many weeks, and six not apparent on examination. of DTPa). Cochrane Database of
vant past or family history. device and second-daily review months later he still has some Should we be initiating antibi- If any contacts come from Systematic Reviews 2007,
Issue 1. Art. No.:
On examination, JS was was organised. mild shadowing in the right otic treatment in such children? such a household or include a CD002744. DOI:
febrile with a temperature of Initially JS improved on this middle lobe on chest X-ray No. This constellation of woman in her last month of 10.1002/14651858.CD0027
38.5°C and his respiratory rate regimen and was more settled (being monitored by the paedi- features is most likely viral in pregnancy (if she delivers, the 44.pub2.
was 48 breaths/minute. ENT after two days. However, at atric team). origin. If the child looks sys- baby could be at risk of per- 3. National Health and
examination was normal. Res- further review (seven days temically well and there are no tussis) the contact should Medical Research Council.
piratory examination revealed after initial presentation), he Questions for the author pulmonary signs, there is no receive antibiotic prophylaxis. I Immunisation Handbook 9th
scattered expiratory wheeze had deteriorated again. He Is there a case for initiating need to start antibiotics. would also offer prophylaxis Edition 2008:
and scattered crackles. JS was was febrile with a temperature amoxycillin treatment together Persistent symptoms, and (and immunisation) to contacts www.health.gov.au/internet/
prescribed amoxycillin and of 37.9°C, tachypnoeic and O2 with a macrolide antibiotic particularly tachypnoea and who have not been immu- immunise/publishing.nsf/
supportive measures and a saturation was 94% on room when a child presents with chest signs, are likely to nised.
How to Treat Quiz Complete this quiz online and fill in the GP evaluation form to earn 2 CPD or PDP points. We no longer accept quizzes
by post or fax.
The mark required to obtain points is 80%. Please note that some questions have more than one correct answer.
Acute respiratory infections in children
— 8 May 2009 www.australiandoctor.com.au/cpd/ for immediate feedback
1. Jared, six months, presents with a two- times in most patients bronchiolitis, bronchitis, croup and contacts of those with whooping cough if the
day history of a fever and cough, preceded d) Recurrent episodes of bronchitis are pneumonia household includes an infant under 24
by a runny nose for a few days. On uncommon c) Detection of the influenza virus by culture is months of age
examination he is tachypnoeic with chest essential for monitoring strains but too slow to d) Adults who received the full course of
wall recessions and widespread crackles 4. Which TWO statements about croup are be a useful bedside test recommended vaccinations in childhood have
and wheeze. Your provisional diagnosis is correct? d) Children under nine years need two doses at lifelong immunity to pertussis
bronchiolitis. Which TWO features would be a) Stridor at rest indicates airway narrowing of at least one month apart the first time they
suggestive of severe infection? least 30% receive influenza vaccine 9. Which TWO statements about causes and
a) Fluid intake <50% of normal in the b) Key features of severe croup include drooling presentation of pneumonia in children are
preceding 24 hours and a toxic appearance 7. Which TWO statements about clinical correct?
b) Respiratory rate of 40 breaths per minute c) All children under 12 months with symptoms features and diagnosis of pertussis infection a) Streptococcus pneumoniae is the most
c) Lethargy of croup should be referred for a paediatric are correct? common cause of pneumonia in preschool-
d) Oxygen saturation of 95% assessment a) Whooping cough is not highly infectious, with aged children
d) Features of severe croup may include only about 30% of unvaccinated household b) Cough is frequently the first symptom in
2. Which TWO statements about lethargy or restlessness contacts becoming infected after exposure children with pneumonia, particularly when
bronchiolitis are correct? b) The characteristic paroxysmal phase of the infection is due to S pneumoniae
a) Bronchiolitis is best diagnosed by chest X-ray 5. Tania, two years, presents with a hoarse whooping cough is usually preceded by a 1- c) Tachypnoea is associated with increased
b) Treatment of bronchiolitis in hospitalised voice, barking cough and stridor, which 2-week catarrhal phase severity of pneumonia and increased
infants is largely supportive with came on overnight. Which TWO statements c) Young infants with pertussis infection can likelihood of underlying consolidation
supplemental oxygen and fluid replacement about the management of croup are present with apnoea even before the cough is d) Children with pneumonia may present with
c) Bronchodilators are a useful additional correct? recognised abdominal pain
therapy in infants under 12 months of age a) Steam inhalation is useful in the d) Bordetella pertussis-specific IgA serology is
d) About 10% of children develop a post- management of mild croup the gold standard test for diagnosis in the 10. Which TWO statements about diagnosing
bronchiolitic syndrome with cough and b) Oral corticosteroids should be prescribed early stages of the disease, especially in and managing pneumonia in children are
wheeze that can recur intermittently for for all but the mildest cases of croup infants correct?
several years c) Children with more severe croup may a) All children with a clinical diagnosis of
require nebulised adrenaline 8. Which TWO statements about managing pneumonia require X-ray confirmation of the
3. Which TWO statements about bronchitis d) There is no role for nebulised budesonide in and preventing pertussis infection are diagnosis
in children are correct? the management of croup correct? b) An FBC will help to distinguish between viral
a) Most cases of acute bronchitis are due to a) Antibiotics will reduce the severity and risk of and bacterial causes of pneumonia
viruses 6. Which THREE statements about influenza complications of whooping cough c) If oral antibiotics are prescribed, amoxycillin is
b) Antitussives and expectorants are useful for in children are correct? b) A person with whooping cough who has been generally the first choice in children under five
symptomatic relief of bronchitis in children a) Children with influenza are not infectious coughing for more than 21 days is no longer years
c) Antibiotics will relieve symptoms of before their symptoms appear infectious d) Macrolide antibiotics may be used as first-line
bronchitis and result in shorter recovery b) Influenza virus may be responsible for c) Antibiotics should be given to household treatment in children over five years
CPD QUIZ UPDATE
The RACGP now requires that a brief GP evaluation form be completed with every quiz to obtain category 2 CPD or PDP points for the 2008-10 triennium. You
can complete this online along with the quiz at www.australiandoctor.com.au. Because this is a requirement, we are no longer able to accept the quiz by post HOW TO TREAT Editor: Dr Wendy Morgan
or fax. However, we have included the quiz questions here for those who like to prepare the answers before completing the quiz online. Co-ordinator: Julian McAllan
Quiz: Dr Wendy Morgan
NEXT WEEK Excessive daytime sleepiness is a common symptom in general practice.The next How to Treat focuses on the primary brain disorders that can cause excessive daytime sleepiness (especially
narcolepsy and idiopathic hypersomnia). The authors are Dr Anup Desai, senior staff specialist, department of respiratory and sleep medicine, Prince of Wales Hospital, Randwick; consultant physician in
private practice, Camperdown (Brain and Mind Research Institute) and Randwick; and clinical senior lecturer, faculty of medicine, University of Sydney; and Dr Ben Kwan, respiratory advanced trainee regis-
trar, Prince of Wales Hospital, Randwick, NSW.
34 | Australian Doctor | 8 May 2009 www.australiandoctor.com.au