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Causes of wheeze
Diagnosis and
management of
asthma
Managing acute
exacerbations
Interval
management of
childhood asthma
Asthma
prevention
The authors
Background
WHEEZE is an extremely common
symptom in children, with up to
40% of children reported as having
at least one episode of wheeze
during childhood. Wheezing is
most common in infancy and
decreases in incidence as children
age.
Wheeze may have many causes
(see table 1, page 33). The most
common is asthma, so it is important to distinguish asthma from
other conditions that may also
cause wheeze. This article discusses
risk factors for developing asthma,
particularly progression from
infant wheeze to childhood asthma,
and the patterns of asthma in children and their management.
What is wheeze and how is
it generated?
Wheeze can be a difficult symptom
to ascertain. Many parents erroneously use the term to describe a
cont’d page 33
DR JOHN MASSIE,
consultant respiratory physician,
department of respiratory
medicine, Royal Children’s
Hospital, Parkville, Victoria.
WHEEZE
DR JO HARRISON,
clinical research fellow,
department of respiratory
medicine, Royal Children’s
Hospital, Parkville, Victoria.
in childhood
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from page 31
variety of noises originating from
the airways, including stridor, snoring or rattling of upper airway
secretions. When taking a history
from families whose first language
is not English it is important to
remember that some languages do
not include a word with exact
equivalence to wheeze.
Considering the significance of
wheeze in research and epidemiological classification, there is little
information about its acoustic
characteristics. Wheezes are continuous adventitious lung sounds
with a ‘musical’ quality, mainly
heard during expiration. The
American Thoracic Society committee on pulmonary nomenclature
defines wheezes as high-pitched
continuous sounds with a domi-
Table 1: Causes of wheeze
Small airways disease
Large airways disease
Asthma
Congenital structural airway disease (eg,
tracheomalacia, bronchomalacia, congenital
tracheal stenosis, vascular ring)
Transient infant wheeze
Mediastinal mass (eg, lymphoma)
Acute viral bronchiolitis
Foreign-body aspiration
Suppurative lung disease
(eg, cystic fibrosis)
Gastro-oesophageal reflux
Congenital heart disease
Chronic neonatal lung disease
nant frequency >400Hz.
The pathophysiological mechanisms that generate wheeze are still
not entirely clear. Its predominance
as an expiratory noise indicates an
intrathoracic origin (as opposed to
stridor, which is predominantly
inspiratory in nature and originates
from the extrathoracic airway).
A recently proposed model of
wheeze production based on mathematical analysis of the stability of
airflow through a collapsible tube
indicates that wheezes are produced by the fluttering of the larger
airways walls, induced by increased
airflow velocity.
This increased velocity may
occur because of localised obstruction or dynamic compression of the
trachea during expiration (caused
by widespread obstruction of
smaller airways). Such small airway
obstruction causes expiration to
become an active process and
pleural pressure to become positive.
Normally there is a progressive
fall in pressure along the airway
from alveoli to the mouth. When
the pleural pressure becomes positive, the pressure outside the
airway (ie, pleural pressure) at
some point becomes greater than
that within and the airway collapses.
The linear velocity of airflow in
small airways is too low to cause
audible sound, even when these are
significantly narrowed. Therefore
the sound that is heard as wheeze
originates in the large airways, even
when the pathology is in the
smaller airways.
This point is clinically relevant,
as there is a temptation to ascribe
wheeze to small airway obstruction
(classically asthma) and to forget
the possibility of large airway
obstruction.
Causes of wheeze
Small airway diseases
children with bronchiolitis
from those with asthma.
However, care must be exercised with use of short-acting
beta2-agonists in children with
bronchiolitis, as they can
worsen hypoxia by exacerbating ventilation-perfusion
(V/Q) mismatching. Generally
they should be avoided if the
diagnosis is certain.
Transient infant wheeze
TRANSIENT infant wheeze
mostly affects young children
with smaller-calibre airways
that develop either because of
familial factors or maternal
smoking during pregnancy.
This group of children
includes those previously
referred to as ‘fat happy
wheezers’.
Risk factors for asthma,
such as atopy and family history, are usually absent in
these children. Typically,
episodes of wheeze occur
spontaneously and often
increase with viral respiratory
tract infections. Most children
outgrow this condition by
school age (six years) as the
airways grow in size.
Children with transient
infant wheeze do not usually
respond to bronchodilators,
and preventive inhaled corticosteroids have been shown
to have no benefit.
Distinguishing between
transient wheeze and asthma
can be very difficult in a
young child who presents
with their first episode of
wheeze. In some cases a therapeutic trial of inhaled bronchodilators (delivered by
metered-dose inhaler [MDI]
and spacer) can be helpful in
making this distinction
because a negative response
makes asthma unlikely.
However, it is important to
remember that parental
reporting of a bronchodilator
response can be unreliable.
Orally administered bronchodilators are ineffective and
have no role in treatment.
Generally the older the
child at the time of their first
episode of wheezing the
greater the chance that asthma
is the cause, but longitudinal
studies have shown that most
children with asthma develop
their initial symptoms in the
first year of life. Given that
most young children with
wheeze do not have asthma,
how can we distinguish
between asthma and transient
wheeze in the young child presenting with wheeze?
Population-based longitudi-
Orally
administered
bronchodilators
are ineffective
and have no role
in treatment [of
children with
transient infant
wheeze].
nal studies in children have
allowed the development of
clinical indices to define
asthma risk in young children.
The chance of the subsequent
development of asthma in a
wheezing child is increased by
up to 5.5 times if there is:
■ A personal history of eczema
or
■ A history of parental asthma
or
■ Two of three risk factors —
personal history of allergic
rhinitis, wheezing that is not
associated with colds and
eosinophilia.
If wheezing episodes are frequent (ie, more than four
episodes a year) asthma is up
to 9.8 times more likely to be
the cause. Importantly, 95%
of children who do not have
these risk factors do not
develop subsequent asthma.
Measuring eosinophil levels
requires a blood test and is
therefore not usually a useful
predictor in the setting of a
GP’s surgery.
Acute viral bronchiolitis
Acute viral bronchiolitis is a
common cause of wheeze in
infants. It occurs most often
in children under 12 months
of age but can occur in those
aged up to 24 months. The
greatest overlap between this
condition and asthma occurs
between 12 and 24 months.
Acute viral bronchiolitis is
caused by respiratory syncytial virus in about 70% of
cases, but other causes include
parainfluenza, influenza and
adenovirus. Seasonal epidemics occur with the highest
incidence between late
autumn and early spring. The
infant usually presents with
fever, coryza and cough and,
in some cases, increasing respiratory difficulty. Auscultation shows widespread crackles and/or wheeze.
The diagnosis is usually clinical, but the causative virus can
be demonstrated by immunofluorescence of a nasopharyngeal aspirate. Proof of viral
infection is usually reserved for
hospitalised infants, epidemiological purposes and only
occasionally for diagnosis.
Only 1% of infants with respiratory syncytial virus infection need hospitalisation.
It is important to distinguish bronchiolitis from
asthma because the only effective therapy for bronchiolitis is
supportive: provision of rest,
supplemental oxygen (if arterial oxygen saturation [SaO2]
is less than 92%) and adequate fluid intake.
A trial of bronchodilators
is rarely worthwhile in children under 12 months of age.
However, it may be worth
considering for the infant who
is close to 12 months, has had
recurrent episodes of wheezing and has strong risk factors
for asthma (such as eczema
and close family history of
asthma).
Between 12 and 24 months
it may only be a response to
bronchodilators that separates
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Suppurative lung disease
Most suppurative lung disease
in children begins in the small
airways. It can present as
recurrent or persistent wheeze
and is often associated with a
moist cough (which may be
most pronounced in the
morning, when secretions
accumulated overnight need
clearing) or increased wheeze
and a moist cough during
viral RTIs that only improve
with antibiotics.
In many cases children with
suppurative lung disease have
been treated for asthma with
bronchodilators and inhaled
corticosteroids despite no
apparent benefit, because their
symptoms include wheeze and
they were wrongly diagnosed
with asthma. This can result
in the diagnosis being delayed
for several years.
The presence of digital clubbing or crackles on physical
examination (outside of an
acute exacerbation of wheeze)
can help distinguish suppurative lung disease from asthma.
Referral to a paediatric respiratory specialist is indicated to
confirm the diagnosis and
supervise treatment.
In some cases, causes such
as cystic fibrosis (remembering that newborn screening
misses 5-10% of cases and not
everyone with cystic fibrosis
has pancreatic insufficiency),
immunodeficiency and primary ciliary dyskinesia (formerly called immotile cilia syndrome) may be identified.
Most children are not
found to have bronchiectasis
when investigated with CT. In
many cases the cause is
unknown and the children are
given the diagnosis of chronic
suppurative bronchitis.
Response to treatment with
antibiotics and chest physiotherapy is usually good,
although some children need
long-term treatment. We suspect that, if left untreated, this
condition would lead to
bronchiectasis.
Gastro-oesophageal reflux and
primary pulmonary aspiration
Gastro-oesophageal reflux
(GOR) may cause wheeze by
several mechanisms, including:
■ Direct aspiration into the
airways and lungs, causing
inflammation.
■ Induction of bronchospasm
by irritation of upper airways.
■ Induction of vagally-mediated reflex bronchospasm by
oesophageal irritation.
Typically, wheeze occurs at
night (when lying down to
sleep) and may be accompanied by vomiting in younger
children and heartburn in
older children. In some cases,
wheezing is the only symptom.
Children with developmental delay (eg, Down syndrome, cerebral palsy) are at
significantly higher risk of
aspiration, either directly
during feeds (primary pulmonary aspiration) or via
GOR.
Wheeze in such patients
should prompt a consideration of GOR and/or aspiration as the cause. However, it
is notoriously difficult to confidently link wheeze to GOR
or direct aspiration and referral to a paediatric respiratory
specialist is usually needed.
Congenital heart disease
Congenital heart disease can
also cause wheeze when pulmonary oedema is present (socalled ‘cardiac asthma’). Distinguishing between cardiac
failure and respiratory disease
is likely to be most difficult in
infants whose major symptoms from cardiac failure are
tachypnoea and poor feeding.
Generally, physical examination should reveal additional
features of heart disease such
as tachycardia, a heart
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How to treat – wheeze in childhood
asthma management, which is probably best shared with a paediatric
respiratory specialist.
from previous page
murmur and hepatomegaly.
notoriously difficult. Prominent
veins in the distribution of the
superior vena cava can be one
additional clinical sign. Spirometry
may show ‘flattening’ of the flowvolume loops, and a chest X-ray
usually confirms a mediastinal
mass compressing the large airways.
Chronic neonatal lung disease
Chronic neonatal lung disease refers
to a condition in infants born prematurely (typically <30 weeks’ gestational age) who continue to require
supplemental oxygen at 36 weeks. It
affects about 30% of babies born
weighing less than 1000g.
These children have abnormal
airway and pulmonary parenchymal
architecture that predisposes them to
wheeze. Wheezing may be spontaneous and reflect the altered small
airways, or occur mostly with viral
RTIs and acute viral bronchiolitis,
which can be more severe in this
group.
Although most infants with
chronic neonatal lung disease
improve with time, many will be
shown (when they are old enough to
perform adequate spirometry) to
have altered pulmonary function tests
that generally show an obstructive
pattern.
They may show improvement with
bronchodilator even though they lack
significant risk factors for asthma,
and often benefit from ‘standard’
Large airway diseases
Structural airway diseases
This group of diseases includes tracheomalacia, bronchomalacia (sometimes concurrent), congenital tracheal
stenosis and vascular rings (when
various arrangements of the great
vessels press on, or surround, the
airway).
Symptoms such as increased work
of breathing, poor feeding and
wheeze usually occur from birth or
within a few weeks of birth. Depending on the level of large airway
obstruction, there may be associated
inspiratory stridor, suggesting an
extrathoracic component to the compressing lesion.
Diagnosing and managing these
conditions is difficult, and referral to
a paediatric respiratory physician is
warranted.
Mediastinal mass
A mediastinal mass compressing the
large airways can present with
wheeze and shortness of breath, masquerading as asthma. Rarely the
Foreign-body aspiration
mass is a congenital lesion, such as a
bronchogenic cyst, but more often it
is a malignancy, such as a lymphoma or leukaemia.
Reduced exercise capacity over
a few days to weeks suggests the
latter, but when growth of the
lesion is rapid, symptoms may present more acutely. Stridor suggests
extrathoracic airway compression
and requires urgent intervention,
as the airway can be critically narrowed.
Making the diagnosis early is
Wheeze due to foreign-body aspiration is typically acute in onset
and unilateral in distribution.
There may be a clear history of
sudden onset of choking while
eating or playing with small toys
in some cases, but in up to 50%
of foreign-body inhalations in small
children no such history is elucidated and the event goes unwitnessed.
Typically, children who inhale
foreign bodies are in the toddler
age range, but inhalation can also
occur in older children. Boys are
more commonly involved than
girls, and the most frequently
inhaled objects are peanuts, closely
followed by small plastic toys.
In the cooler months many children have coexistent viral URTIs
and it can be tempting to attribute
wheezing to causes such as a viral
infection or an acute exacerbation
of asthma. The history of sudden
onset, the unilateral nature of the
wheeze or reduced air entry, and
the lack of risk factors for asthma
should prompt a rethink of these
diagnoses.
When foreign-body aspiration is
suspected, a chest X-ray, taken on
inspiration and expiration, is
required to help confirm the diagnosis. The X-ray should include the
upper airway.
Most foreign bodies are not
radio-opaque, but the expiratory
film may demonstrate air trapping
on the affected side, due to a ballvalve effect of the foreign body.
However, the X-ray may be inconclusive, partly due to the difficulty
of capturing images in the correct
phase of respiration in an infant.
If the history is suggestive of foreign-body aspiration and the child
has ongoing symptoms (classically
cough) or signs (eg, wheeze) or a
suggestive X-ray, urgent referral is
needed for rigid bronchoscopy (see
Authors’ case study, A two-yearold with a foreign body, page 36).
Diagnosis and management of asthma
Clinical features
PERSISTENT wheeze is
much more likely to be due
to asthma if it continues to
school age and if there are
other risk factors such as
atopy in the child or immediate family.
A thorough history is crucial for diagnosing asthma
in children. Investigations
(discussed below) are often
not possible in young children and may be normal in
older children with asthma.
Classically, children with
asthma develop a combination of wheeze, shortness of
breath, chest tightness and
cough after exposure to
known triggers. The
reported or observed
response to bronchodilators
is a helpful part of the history.
In children, viral infections
are the most common triggers, precipitating attacks in
up to 90% of cases. Most
children with asthma also
have symptoms during or
after exercise — especially
on colder days when the air
is drier.
As children get older,
allergies play an increasing
role in triggering symptoms.
A history of eczema and
other allergic manifestations
in the child and immediate
family provide supportive
evidence for the diagnosis of
asthma.
Type of asthma
Pattern
Infrequent
episodic asthma
(75% of children)
Episodes more than six weeks apart
Symptoms rare between attacks
Attacks are not usually severe
Normal examination and lung
function between attacks
Frequent
Episodes less than six weeks apart
episodic asthma Increasing frequency of symptoms
(20% of children) between attacks
Attacks are more problematic
Normal examination and lung
function between attacks
Persistent asthma Episodes less than six weeks apart
(5% of children)
Daytime symptoms on more than
two days a week
Nocturnal symptoms on more
than one night a week
May have abnormal lung function
between episodes
Multiple emergency department
visits or hospital admissions
Allergy tests
*From the Asthma Management Handbook 2002 (see Online resources, page 36)
Establishing the pattern
of asthma in children
The pattern of asthma in
children distinguishes it from
asthma in adults and forms
the basis for treatment and
prognosis. The history
enables the clinician to
establish the pattern of
asthma (table 2).
Specific questions to ask
34
The most commonly used
challenge is exercise (with a
standardised protocol)
although challenges with
hypertonic saline and, more
recently, dry powder mannitol are gaining favour. Histamine and methacholine
challenges are rarely used in
clinical situations.
Table 2: Patterns of asthma in children*
| Australian Doctor | 4 August 2006
should include frequency of:
■ Exacerbations.
■ Sleep disturbance due to
asthma.
■ Early morning symptoms.
■ Symptoms in relation to
exercise or activity.
■ Bronchodilator use.
Investigations for
diagnosing asthma
in children
Tests of pulmonary function
In school-aged children (≥6
years) lung function testing
may be helpful in confirming the diagnosis of asthma.
Useful tests include spirometry, particularly FEV1 and
the ratio of FEV1 to FVC,
both of which are reduced
in asthma. A significant
increase in FEV1 (eg, ≥12%)
after administration of a
bronchodilator provides further evidence of reversible
airway obstruction.
Care needs to be taken in
performing and interpreting
spirometry in children, as
they often find it difficult to
understand the appropriate
commands. However, it is
worth persisting and letting
the child get used to the
technique so that reliable
results can eventually be generated.
It is also important to
remember that spirometry
may be normal if the measurement is made between
episodes of bronchospasm.
Thus, normal results do not
exclude a diagnosis of
asthma. However, if results
are repeatedly normal when
tested during symptoms, the
diagnosis of asthma must be
placed in doubt.
Tests of bronchial hyperresponsiveness may be helpful in some cases when the
diagnosis of asthma is in
doubt. These should be performed at a laboratory experienced in testing children,
and the opinion of a paediatric respiratory specialist
may be warranted.
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Allergy tests may be helpful
when seeking causal factors,
and in making a general
diagnosis of atopy, but the
presence of allergy is not
essential to the diagnosis of
asthma.
Allergy tests should look
for sensitisation to aeroallergens such as house-dust
mite, dog and cat dander
and grasses. Food allergies,
while helpful in defining an
atopic child, are generally
not causally associated with
asthma. Tests include skin
prick testing and the radioallergosorbent test (RAST).
Chest X-ray
Chest X-rays are not useful
in making a diagnosis of
asthma, although they may
play a role in excluding
other diagnoses, such as foreign-body inhalation or suppurative lung disease. They
should be reserved for children who have signs or
symptoms that arouse suspicion of alternative diagnoses,
or for children whose symptoms do not respond to routine asthma treatment.
Treating asthma in
children
The management of asthma
in children differs from that
in adults and this difference
is reflected in the varying patterns of childhood asthma,
suggesting that we are not
dealing with an homogeneous
disease process.
Childhood asthma is dominated by the presence of
virus-induced exacerbations,
even in children with persistent (‘adult style’) disease.
Furthermore, the activity
levels of children are different
to those in adults and may
sometimes influence therapy.
The goals of asthma management should be to allow
children to be symptom free
and able to lead as normal a
life as possible, while using
the lowest dose of medication possible to minimise the
risk of side effects. Managing asthma includes treating
exacerbations and interval
symptoms.
Response to treatment
A therapeutic trial of appropriately delivered therapy
can be helpful in confirming
the diagnosis of asthma in
children. To determine
whether the symptoms are
caused by bronchospasm, a
trial of inhaled short-acting
beta2 agonists is warranted,
looking for a rapid response
(1-3 minutes after dose) that
lasts 3-4 hours.
It may still be difficult to
be certain about the diagnosis in some cases and a
supervised trial of inhaled
corticosteroids over 4-6
weeks is appropriate. During
the trial it is best not to use a
label of asthma, reserving
this until the diagnosis is
confirmed.
Failure to respond to conventional treatment should
prompt consideration of
alternative diagnoses. It is
also important to remember
that apparent improvement
after the introduction of
inhaled corticosteroids may
be coincidental.
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Managing acute exacerbations
THE standard management
of acute exacerbations in
children is a combination of
prn short-acting inhaled
beta2 agonist (bronchodilator) and oral prednisolone
(Panafcortelone, Predmix,
Predsolone,
Redipred,
Solone) (see table 3).
Inhaled medication is best
delivered by puffer and
spacer unless the child is too
ill to sit up and co-operate,
in which case continuous
nebulised
salbutamol
(Airomir, Asmol, Butamol,
Epaq, Ventolin) should be
used.
Ipratroprium (Aeron,
Atrovent, Ipratropium, Ipra-
Table 3: Managing acute exacerbations of asthma
in children
Bronchodilator (as needed)
Salbutamol (by MDI) (100µg/puff)
■
Age < six years: six puffs via small-volume spacer
■
Age ≥ six years: 12 puffs via large-volume spacer
Terbutaline turbuhaler (500µg/puff) (age > eight years)
■
Age > eight years: six puffs
Prednisolone
■
1mg/kg (maximum 50mg) daily for three days
trin, Ipravent) has very little
role outside the setting of a
severe exacerbation and in
these cases may be used in
conjunction with salbutamol
as a repeated treatment
every 20 minutes (up to
three doses).
Oral prednisolone has
been part of the acute exacerbation paradigm for some
time. Treatment duration of
three days does not require
weaning and has been
chosen because that is the
usual duration of acute
symptoms. If a child continues to have significant symptoms, prednisolone can be
used for a longer period of
time.
Side effects from short
courses of prednisolone such
as these are negligible: use
fewer than four times a year
has been shown to be safe.
Parents should be taught
to recognise the symptoms
of an exacerbation and
empowered to initiate treatment with prednisolone.
There is no value in doubling the dose of inhaled
corticosteroids (if the child
is using them) or of introducing them acutely, as the
onset of action takes weeks.
Prednisolone may not be
effective in younger children
(<5 years) who wheeze with
viral RTIs even when there
has been an apparent bronchodilator response. This is
probably because ‘asthma’, as
we think of it, is a symptom
complex, not a diagnosis.
These children are simply
‘wheezing with colds’
although the phenotype is
similar to ‘true asthma’. Separating the two is difficult
and may rely on the presence
of risk factors (atopy, family
history) or simply be a
matter of time for the
‘wheezers with colds’ to
grow out of it.
There is some emerging
evidence that montelukast
(Singulair), which has a relatively rapid onset of action,
may shorten the duration of
symptoms in this group.
However, it is still too early
to alter the current paradigm.
Interval management of childhood asthma
Infrequent episodic asthma
CHILDREN with infrequent
episodic asthma can be managed
with reliever medication such as
salbutamol 100-200µg and terbutaline (Bricanyl) on a prn basis only.
Frequent episodic asthma
It is worth considering a trial of daily
preventer therapy for children with
frequent episodic asthma in an
attempt to reduce the frequency and
severity of exacerbations. However,
such therapy is often unsuccessful
and the only approach remains to
optimise management of acute
events.
Preventive therapy should be tried
(as per the schedule for mild persistent asthma) using either low-dose
inhaled corticosteroids or montelukast.
Mild persistent asthma
There are two choices for preventive treatment for mild persistent
asthma — low-dose inhaled corticosteroid or a leukotriene-receptor
antagonist such as montelukast.
Despite the inclusion of sodium
cromoglycate (Cromese, Intal) and
nedocromil sodium (Tilade) in several national guidelines on asthma
management, they have not been
proven to be effective and we cannot
recommended them.
Inhaled corticosteroids are the
preventer of choice for most children. Four drugs are available:
■ Fluticasone (Flixotide).
■ Beclomethasone (Qvar).
■ Budesonide (Pulmicort).
■ Ciclesonide (Alvesco).
Although any of the above may
be started, decisions about drug
delivery devices (eg, MDI and spacer
vs dry powder inhaler) and adherence (device, once daily vs twice
daily) may be factors that determine
choice of medication.
It is important to remember that
fluticasone, ciclesonide and
beclamethasone are twice as potent
as budesonide, ie,100µg fluticasone
is equivalent to 200µg of budesonide. A standard starting dosage
would be, for example, fluticasone
100-200µg/day.
At these dosages, 80-90% of treatment effect occurs and serious side
effects are rare. It is important to
explain to parents that it may take
up to six weeks before the maximal
benefits of treatment are apparent.
Table 4: Interval management of asthma in children
Pattern of childhood asthma
Treatment
Infrequent episodic asthma
As-required bronchodilators only
Frequent episodic asthma
Patient may benefit from preventive therapy,
eg, low-dose inhaled corticosteroids or
leukotriene-receptor antagonist
Persistent asthma
Mild
Low-dose inhaled corticosteroids (fluticasone
100-200µg/day or equivalent) or a
leukotriene-receptor antagonist
Moderate
Inhaled corticosteroids (fluticasone
200-500µg/day or equivalent) ± a LABA
Severe
Inhaled corticosteroids (fluticasone up to
500µg/day or equivalent) + a LABA
Table 5: Route of drug delivery
General tips for children with
persistent asthma
Age
Route of
administration
<2 years 2-6 years
6-8 years
8 years
and older
MDI + large-volume
spacer
Yes
Yes
Turbuhaler
Some children
Yes
Accuhaler
Some children
Yes
MDI, small-volume Yes
spacer + mask
May drop
the mask at
4 years old
MDI (alone)
Only for
bronchodilator
Autohaler
Yes
Oral
Yes
Preventive therapy should be
started with inhaled corticosteroids
alone. Not only is this a PBS requirement but it makes sense to gauge
the effect of a single therapy before
the addition of a second (eg, a longacting beta2 agonist [LABA]). Budesonide and ciclesonide can be used
once daily, which may be advantageous for some patients.
Montelukast is a legitimate starting medication for children with
mild persistent asthma. It has PBS
listing for children aged 2-14 years
(authority required) for this indication, which makes the price to
consumers equivalent to that of
inhaled corticosteroids. The onset
of action is rapid (within a few
days), as it has both a bronchodilator and an anti-inflammatory action.
In children with mild persistent
asthma, the choice between an
inhaled corticosteroid and a
leukotriene-receptor antagonist is
Yes
Yes
usually one based on the choice of
drug delivery system, with the
patient’s (and parents’!) choice likely
to positively benefit adherence.
Moderate or severe persistent
asthma
The starting point for children
judged to have moderate or severe
persistent asthma, and who have not
been treated for some reason, is
inhaled corticosteroids. Even modest
dosages such as fluticasone
200µg/day (or equivalent) may be
adequate, but it is possible to start
with higher doses and back-titrate
after control is achieved.
When adequate control of symptoms is not achieved with inhaled
corticosteroids alone, a long-acting
beta2 agonist such as salmeterol
(Serevent) or eformoterol (Foradile,
Oxis) should be added next.
The PBS requires that this is done
using a separate inhaler initially. The
patient should be reviewed to assess
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After symptoms have been well
controlled for 3-6 months,
consider reducing the therapy,
starting with reducing the dose of
inhaled corticosteroid.
■ Every time a child requires a
step-up of therapy, reconsider the
diagnosis of asthma, adherence
to therapy and form of drug
delivery.
■ If a child is poorly controlled on
maximal therapy (fluticasone
500µg/day or equivalent) + a
LABA, they should be referred to
a paediatric respiratory physician.
■
the success of this addition before
combination inhalers (Symbicort or
Serevent) are used.
LABAs should be discontinued if
there is no response. The dose of
inhaled corticosteroid (with or without a LABA) can be increased if control is poor, but dosages above
500µg/day of fluticasone (or equivalent) rarely help.
There is no benefit in adding montelukast to inhaled corticosteroids
for patients with poorly controlled
asthma.
Side effects of treatment
There has been increasing concern
about potential side effects of
inhaled corticosteroids, such as
growth retardation and osteoporosis.
However, it should be remembered
that under-treatment of persistent
asthma is potentially associated with
far greater risks than those associated with low-dose inhaled corticosteroids.
We know that increasing the
dosage of fluticasone above
500µg/day (or equivalent) results
in minimal clinical benefit in most
children but does increase the risk
of side effects.
Recent trials have shown that,
despite an initial reduction in
expected growth of about 1cm over
12 months in children treated with
400µg/day budesonide, their subsequent growth velocity was normal
and they achieved expected adult
height. Conversely, poorly controlled
asthma results in impaired growth.
Nonetheless, it is possible that
some children may be susceptible
to the effects of inhaled corticosteroids at lower doses and be at
risk of growth retardation. Therefore all children taking inhaled
steroids should have their growth
monitored every 6-12 months.
Another concern is the effect of
inhaled corticosteroids on bone
metabolism and risk of osteoporosis. To date, the evidence shows
minimal effect when dosages of fluticasone <500µg/day or equivalent
are used.
There are a handful of case
reports linking moderate-high
dosage (fluticasone >500µg/day or
equivalent) of inhaled corticosteroids with adrenal suppression
in children. As a minimum, children regularly taking ≥500µg/day
of fluticasone (or equivalent)
should have a screening earlymorning cortisol after three months
of therapy and inform medical staff
of their treatment dosages in the
event of a serious illness or anaesthetic.
Route of drug delivery
Choice of delivery route of medication is an essential component of
management. Delivery systems and
appropriate ages are presented in
table 5. Issues to consider include:
■ Patient choice (to optimise adherence).
■ Factors affecting maximisation of
drug delivery to the lower airways
(use of a spacer with an MDI).
■ Minimising oropharyngeal deposition (use of a spacer with an
MDI).
In many cases drug delivery
should be the first consideration
and the choice of medication
should suit the preferred form of
delivery.
4 August 2006 | Australian Doctor |
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How to treat – wheeze in childhood
Asthma prevention
MANY parents want to
know what they can do to
prevent their child developing asthma, or how they can
modify its severity.
The most important
advice relates to smoking
cessation. Avoidance of
tobacco smoke exposure in
utero significantly reduces
the risk of a child developing
transient infant wheeze.
Passive smoke exposure
has been shown to increase
the risk of asthma and respiratory symptoms in schoolchildren. Breastfeeding has a
protective effect in asthma
development (along with
other health benefits to the
child) and should be encouraged.
Allergen avoidance is a
controversial area and it is
difficult to give dogmatic
advice to parents. Obviously
if a child develops wheeze
after exposure to specific
animals, such exposure
should be avoided.
Measures to reduce environmental house dust mite
exposure are costly and the
evidence that they improve
asthma symptoms is controversial. There is some evidence that treating patients
who also have chronic rhinitis with intranasal corticosteroids may improve
asthma control.
Allergen immunotherapy
has been best proven to help
patients (including children)
who have allergic rhinitis,
but not those with asthma.
Figure 1: Asthma Action Plan
the treating physician.
Provide a written reminder
of maintenance therapy.
■ Give information about the
management of acute
episodes.
Patients, particularly adolescents, should be empowered to call for an ambulance in the event of a severe
exacerbation.
It is important that every
child with asthma is
reviewed regularly. Aims
include:
■ Reviewing the appropriateness of the diagnosis.
■ Assessing the level of control.
■ Assessing adherence.
■ Reviewing inhaler technique.
■ Monitoring growth.
■ Reviewing the appropriateness of medications.
■ Education.
The written asthma plan
should be reviewed and
updated regularly.
It is vitally important that
parents receive sufficient
education about asthma.
They should be provided
with information on the natural history of asthma in
children, the aims of treatment, the duration of treatment and the risks compared
with the benefits of therapy.
A better understanding of
the rationale for their child’s
treatment promotes adherence to prescribed therapy.
■
For: ....................................................................................
Prepared by: ...................................................................... on: ........... / ....... / .............
Preventive treatment (everyday — when sick or well)
Take: 1)
..........................................................
............................
............. times a day
2)
..........................................................
............................
............. times a day
3)
..........................................................
............................
............. times a day
Before sport or exercise take: ...................................................................
When you get mild symptoms
In additional to regular preventive treatment, take:
................................................
............... puffs ............... as often as ............ hourly, as needed ............
When symptoms are more troublesome
................................................
............... puffs ............... as often as ............ hourly, as needed ............
Always use your spacer.
IF:
you need to take your Ventolin/Bricanyl more often than 3-4 hourly
OR
you need Ventolin/Bricanyl 3-4 hourly regularly for more than 6 doses,
THEN
Give: prednisolone ......................mg as a single dose daily for up to 3 days
If you have a very bad attack
Take: ............... puffs of Ventolin/Bricanyl every 15 minutes while arranging urgent transport to hospital
When to seek help from your doctor or hospital
■
■
■
■
If you have a bad attack and are worried
If you need Ventolin/Bricanyl more than every 2-3 hours
If wheezing persists for more than 24 hours and is not settling
If you get little or no relief from Ventolin/Bricanyl or symptoms worsen suddenly, then:
DO NOT STAY AT HOME — SEEK MEDICAL HELP IMMEDIATELY
Keep this plan readily available at all times and give copies to others involved in care of the patient.
The main reason for this is
that children with mildmoderate asthma can be
treated effectively, safely
and relatively cheaply with
inhaled corticosteroids or
leukotriene-receptor antagonists.
In children with more
severe asthma there are significant safety concerns with
use of allergen immuno-
therapy, as fatal reactions
have been reported.
Asthma management
plans
All children with asthma
should be provided with a
written asthma plan (figure 1),
which should be easy to read,
concise and individualised to
the patient. It should:
■ Reinforce advice given by
Natural history
Most children with asthma
improve over time. This is
because most (75%) have
infrequent episodic asthma,
without atopy or a family
history, and tend to stop
having episodes by age 10.
Of those with persistent
asthma, many have atopy
or a family history of
asthma/atopy and are more
likely to have persistent
asthma into adulthood.
However, this outcome
should never be assumed
and, when children are well
controlled, their therapy
should be weaned and, if
possible, stopped. Otherwise
it is not possible to know
whether good control is due
to treatment or natural
improvement of asthma.
There has been much
interest in attempting to halt
the progression from intermittent wheeze to persistent
asthma. Recent work has
shown that regular inhaled
corticosteroids, given prophylactically to preschool
children who have recurrent
wheezing and are at high
risk of asthma, reduce symptoms and frequency of acute
exacerbations but do not
modify the natural history of
asthma.
Other work has shown
that giving wheezy infants
at high risk of asthma intermittent two-week courses
of inhaled steroids during
wheezing episodes had
no benefit in reducing
symptoms or in preventing
progression to persistent
wheezing.
Authors’ case studies
A toddler with asthma
KIAN, 17 months, was taken to his
GP because of his mother’s concerns
about his wheezing. He had developed a fever and coryza three days
before and become increasingly
wheezy over the preceding 48 hours,
with laboured breathing.
On further questioning, his mother
described recurrent episodes of
wheeze since 10 months of age.
These usually occurred when he had
an URTI and would be accompanied
by a cough and coryza.
Kian had been delivered at term
after an uneventful pregnancy. He
had eczema as a baby, which cleared
after age one. His father has asthma
and his older sister has eczema. Neither parent smokes.
On examination, Kian was well
grown with no finger clubbing or
chest deformity. He was tachypnoeic
with subcostal recession and widespread expiratory wheeze on auscultation.
He responded well to six inhalations of salbutamol via a smallvolume spacer and mask at the GP’s
surgery. His wheeze disappeared and
his respiratory distress improved
markedly. The salbutamol was
administered at home with instructions on its delivery. When reviewed
the next day, Kian was much better.
A two-year-old with a foreign body
ADAM, two years, presented with a
36
| Australian Doctor | 4 August 2006
Figure 2: Chest X-rays showing unilateral hyperinflation on expiration in child with foreign body in right main bronchus
24-hour history of wheeze, which
began the previous day while playing
at his cousin’s house. He had never
been wheezy in the past. Adam was
otherwise well, with no coryza,
cough or fever. He was delivered at
term after an uncomplicated pregnancy. He had no past medical history of note. His parents were
healthy and he had no siblings.
On examination Adam looked
well. He was thriving, with no finger
clubbing or chest deformity. Auscultation revealed a bilateral wheeze,
which was loudest on the right side.
The GP gave him six inhalations
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of salbutamol via a small-volume
spacer and mask, but the wheeze
persisted. Inspiratory and expiratory
chest X-ray films were ordered
because of concern about the possibility of a foreign body. The X-ray
showed unilateral hyperinflation on
the right side, particularly obvious
on expiration (figure 2).
A foreign body was suspected and
Adam was referred for rigid bronchoscopy. This was performed that
evening and a plastic wheel from a
toy car was removed from his right
main bronchus. Adam remained well
thereafter.
Online resources
National Asthma Council
Australia. Asthma Management Handbook 2002.
www.nationalasthma.org.
au/html/management/amh
n Asthma Foundations of
Australia:
www.asthmaaustralia.
org.au
n
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How to treat – wheeze in childhood
GP’s contribution
Case study
DR LIZ MARLES
Redfern, NSW
JEREMY, 12 months, is
brought in by his mother for
the fourth time in two
weeks. She is concerned
that he has a “wheeze”
that is not improving. Last
night he barely slept, so
she gave him her elder son’s
Ventolin through a spacer, but
this had little effect.
When seen before, Jeremy
had been diagnosed with a
viral illness on the basis of
fever, runny nose and cough.
Before this episode, he had no
history of wheezing, although
he did have moderate hyaline
membrane disease requiring
oxygen when he was born at
35 weeks’ gestation.
He is still breastfeeding
twice a day but has also
been on solids for six
months, and is crawling but
not walking. Jeremy’s
brother was diagnosed with
mild episodic asthma a year
ago at age three years, and
his father also had mild
asthma as a child.
On examination, Jeremy is
afebrile and appears happy.
He is quite tachypnoeic, with
some subcostal and intercostal
recession, and his breathing is
rattly, although
there is no audible wheeze. On
auscultation he has multiple
upper airway transmitted
sounds and there is only a
mild audible expiratory
wheeze.
Questions for the authors
Is wheezing always present in
bronchiolitis?
No. Although wheeze is a
common finding in babies
with bronchiolitis, a proportion will only have generalised
crackles audible on auscultation. Very young babies can
present with apnoea as the
only manifestation of respiratory syncitial virus bronchiolitis. Thus the absence of
wheeze does not preclude the
diagnosis if the other clinical
features are suggestive.
Under what circumstances are
How to Treat Quiz
Wheeze in childhood — 4 August 2006
1. Which TWO statements about asthma in
childhood are correct?
❏ a) Up to 15% of children have at least one
episode of wheeze
❏ b) Even when the pathology responsible for
causing wheeze occurs in the smaller
airways, the sound originates in the large
airways
❏ c) Most children with asthma develop their
first symptoms in the third or fourth year of
life
❏ d) Regular inhaled corticosteroids given
prophylactically to preschool children who
have recurrent wheezing and are at high risk
of asthma do not modify the natural history
of asthma
2. Todd brings his seven-month-old son,
Jamie, to you because of wheezing. Jamie is
thriving and examination is normal apart
from minimal bilateral wheeze. Todd asks
which factors would make asthma more
likely to be causing Jamie’s wheeze. Which
THREE responses are you likely to give?
❏ a) A personal history of eczema
❏ b) A history of asthma in Todd
❏ c) A history of recurrent viral URTIs in Jamie
❏ d) Wheezing episodes in Jamie not
associated with colds
3. Jamie and Todd do not have risk factors
for asthma and you think transient infant
wheeze is more likely to be the diagnosis.
Which ONE management option are you
most likely to consider for Jamie at this
stage?
❏ a) An oral bronchodilator
❏ b) A short course of oral steroids
❏ c) A trial of preventive inhaled
corticosteroids
❏ d) Explanation about transient infant
wheeze and review if Jamie’s wheeze
worsens
4. Jamie’s intermittent wheeze continues
over the next eight months, and a trial of
inhaled bronchodilator does not change his
symptoms. Which THREE findings would
be consistent with suppurative lung
disease as a possible cause of his
symptoms?
❏ a) Lung crackles between episodes of
wheezing
❏ b) Prolonged wheeze and productive cough
during and after viral RTIs, which only
improve with antibiotics
❏ c) A dry cough that is worse in the evenings
❏ d) Jamie’s lack of response to asthma
therapy
investigations warranted to
preclude inhaled foreign
body?
Investigations should be performed in any child with a history strongly suggestive of foreign-body aspiration. This
includes those where aspiration has been witnessed as well
as those with acute onset of
symptoms, particularly if
accompanied by unilateral
signs, such as wheeze and
reduced air entry.
Initial investigation would
be inspiratory and expiratory
chest X-rays. If the history
suggests foreign-body aspiration and the child has ongoing symptoms (classically
cough) or signs (eg, wheeze,
particularly if unilateral) or a
suggestive X-ray, urgent referral is needed for rigid bronchoscopy.
What is the appropriate treatment for Jeremy at this stage?
Jeremy’s mother has
already given him a therapeutic trial of bronchodilator to which he failed to
respond. As Jeremy does not
appear too distressed, and
presuming there is nothing
to suggest hypoxia or dehy-
dration, he should be managed with supportive treatment only, and his mother
reassured.
Are children with bronchiolitis
likely to show any response to
oral prednisolone?
No. Oral corticosteroids
have been studied in the treatment of bronchiolitis in the
hope that their anti-inflammatory effect may help relieve
airway swelling and reduce
obstruction. However, randomised controlled trials,
meta-analyses and systemic
reviews have failed to show
any benefit for the treatment
of young children with bronchiolitis.
General questions for the
authors
With the advent of montelukast as a preventive agent
for mild persistent asthma, is
there still a role for sodium
cromoglycate?
No, sodium cromoglycate is
of no proven benefit in the
treatment of asthma of any
severity.
How are children who experience moderate episodic asthma
associated with viral infections
(perhaps 3-4 times a year) and
with no interval symptoms
most appropriately managed?
Children with this pattern
of asthma are best managed
by use of reliever medication
(such as salbutamol 100200mg and terbutaline
[Bricanyl]) as required for their
symptoms, in addition to a
short course (eg, three days)
of oral prednisolone.
If their episodes become
more frequent, it would be
appropriate to start a trial of
daily inhaled corticosteroids.
However, it must be remembered that this therapy may
not prove to be beneficial, in
which case it should be discontinued.
At what age are spirometry
and peak-flow measurements
relevant in assessing childhood
asthma?
Spirometry can be performed in children from the
age of six years in a laboratory with personnel experienced in testing children.
There is no role for peakflow measurement in the
management most children
with asthma.
INSTRUCTIONS
Complete this quiz to earn 2 CPD points and/or 1 PDP point by marking the correct answer(s)
with an X on this form. Fill in your contact details and return to us by fax or free post.
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How to Treat quiz
Reply Paid 60416
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5. Which TWO circumstances would make
an inhaled foreign body unlikely to be the
cause of wheezing in an infant?
❏ a) Gradual onset of wheeze
❏ b) Reduced air entry in both lungs
❏ c) No history of foreign-body inhalation
❏ d) Normal chest X-ray
6. Sadie brings her five-year-old son,
Garth, to see you because of
increasing episodes of wheeze. Which
information about Garth’s symptoms
would suggest a diagnosis of asthma
(choose TWO)?
❏ a) Episodes of wheeze triggered by
URTIs
❏ b) Recent onset of stridor
❏ c) Episodes of recurrent tonsillitis
❏ d) Cough after exercise
7. You think Garth is likely to have asthma.
Information about the frequency of which
THREE of the following would help you to
establish the pattern of his asthma?
❏ a) Sleep disturbance because of asthma
❏ b) Early morning symptoms
❏ c) Bronchodilator use
❏ d) Nasal symptoms such as sneezing and
blockage
ONLINE
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for immediate feedback
8. You perform spirometry and Garth’s
results are normal. Which THREE
factors may have influenced the
results?
❏ a) Garth’s sex
❏ b) Tests were performed between episodes
❏ c) Incorrect diagnosis
❏ d) Garth’s age
9. Which ONE of the following tests would
you order if wheezing persisted and
the diagnosis of asthma was still in
doubt?
❏ a) Chest X-ray
❏ b) Bronchial hyperresponsiveness
❏ c) Allergy tests
❏ d) ESR
10. Which TWO medications are most
appropriate for treatment of moderately
severe acute exacerbation of asthma in a
child?
❏ a) Short-acting inhaled beta2-agonist via a
puffer and spacer as required
❏ b) Oral prednisolone at a dose of 1mg/kg
(to a maximum of 50mg daily), for three days
❏ c) Inhaled steroid at maximum dosage
❏ d) Inhaled ipratroprium bromide for three
doses
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HOW TO TREAT Editor: Dr Lynn Buglar
Co-ordinator: Julian McAllan
Quiz: Dr Lynn Buglar
The mark required to obtain points is 80%. Please note that some questions have more than one correct answer. Your CPD activity will be updated on your RACGP records every January, April, July and October.
NEXT WEEK The next How to Treat confronts the challenges faced by couples who experience stillbirth and sudden unexpected death in infancy. The authors are Dr Jacqueline M Scurlock, general
paediatrician, Princess Margaret Hospital for Children, and chairman, scientific advisory committee, SIDS & Kids, WA; Belinda Jennings, perinatal loss midwife and member of the scientific
advisory committee SIDS & Kids, WA; Judi Nolte, grief counsellor, SIDS & Kids, and clinical nurse, ICU, Princess Margaret Hospital, WA; and Dr Jane Freemantle, senior researcher and epidemiologist,
Telethon Institute for Child Health Research, WA.
38
| Australian Doctor | 4 August 2006
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