PERSONAL PRACTICE

Wheeze in a preschool childJonathan Grigg

What do you do?

Peter, brings his 18 month old son, Alex to see his GP with

a history of wheeze. Alex had an uneventful birth at term. His

immunisations are up to date, and he was exclusively breast fed

up to 4 months of age. He had ‘‘dry skin’’ on his scalp soon after

birth, which resolved by 6 weeks of age. Four weeks ago while

on a family holiday, he developed a cold with rhinitis and within

4 hrs was very wheezy. He was reviewed at local hospital’s A&E

department and admitted. He was treated with regular nebu-

lisers and discharged the next day with no prescribed medica-

tions. Since this episode he has been very well, with no further

wheeze.

Key points in history

Is this wheeze?

In Alex’s case the history of wheeze (a high pitched whistling

sound from the intrathoracic airways that is heard mainly during

expiration) is likely to be accurate since it was diagnosed by

a clinician. Parents, especially those in ethnic minority groups or

socioeconomically deprived families, may find it difficult to

separate wheeze from other causes of noisy breathing. For

example, infants with colds often develop rattly sounds from

mucus accumulation in the larger airways e which may mask

underlying wheeze, or be misclassified as wheeze. A helpful

question is whether the child has ‘‘breathing that makes a high-

pitched whistling or squeaking sound from the chest, not the

throat.’’

In young infants (< 5 months) it may be difficult to distin-

guish respiratory syncytial virus (RSV) bronchiolitis from viral-

triggered wheeze. In general, RSV bronchiolitis is characterised

by widespread inspiratory crackles, whereas virus-triggered

wheeze has few or no crackles, especially before bronchodilator

therapy. The potential for overlap in signs between RSV bron-

chiolitis and viral-wheeze is one reason why most randomised

controlled trials of therapies for viral-wheeze have a lower age

limit of 10 months.

Jonathan Grigg MD FRCPCH is Professor of Paediatric Respiratory and

Environmental Medicine, and Queen Mary University London, and an

honorary consultant paediatrician at the Royal London Hospital,

Whitechapel and Centre for Paediatrics, Blizard Institute of Cell and

Molecular Science,4 Newark Street, London E1 2AT, UK. Conflicts of

interest Over the last 3 years, the author has been paid £300 and

travelling expenses of £200 to give an educational talk by Glaxo. He

received an honorarium of £1300, and traveling and hotel expenses of

£500 from AstraZenca to attend a symposium.

PAEDIATRICS AND CHILD HEALTH 20:4 186

What is the pattern of wheeze?

There are two phenotypes of preschool wheeze, i) intermittent

viral-triggered wheeze (viral-wheeze) and ii) multi-trigger

wheeze. Viral wheeze, by far the most prevalent phenotype in

children less than 6 years of age, is characterised by short

episodes of wheeze associated exclusively with colds, inter-

spersed by asymptomatic periods. Multi-trigger wheeze resem-

bles atopic asthma in older children e with wheeze triggered not

only by colds, but also by non-viral triggers such as pets, and

running around. In Alex’s case, there was no history of previous

wheeze and the attack could be the first presentation of either

phenotype. Questions to ask are;

� does Alex wheeze only with colds with no wheeze between

attacks?

If there is a history of wheeze between colds:

� is wheeze triggered by exposure to animals, or after running

around?

� does he have a dry irritant cough after running around, or at

night?

Are there features to suggest an alterative diagnosis?

The possibility of structural abnormalities, foreign body and

major diseases such as cystic fibrosis (CF) and primary ciliary

dyskinesia (PCD) should be borne in mind, although Alex’s

history is highly suggestive of preschool wheeze (see differen-

tial). Specific questions should include;

� Does your child have a long-term wet cough? (CF and PCD)

� Did the attack of wheeze occur after a choking episode?

(foreign body)

� Does your child have noisy breathing between wheeze

attacks (structural abnormality)

� Does your child have bouts of dry coughing (post-pertussis)

Alex’s infant record should be looked at to ensure that he is

not failing to thrive.

Is there a history to suggest an atopic tendency?

A history of severe eczema slightly increases the risk of Alex

developing multi-trigger wheeze. However mild eczema or cradle

cap provides has no prognostic significance.

Other relevant history?

The family history of asthma should be obtained, but usually

does not help with diagnosis or treatment of preschool wheeze.

Exposure to passive cigarette smoke is a vulnerability factor for

both phenotypes of preschool wheeze. Parents should be

unequivocally told that their smoking, or allowing friends to

smoke near their child, will increase the frequency and severity of

attacks. If a parent smokes, cessation therapy should be offered.

Findings from history

On direct questioning, Alex had one additional previous episode

of wheeze, at 12 months of age, which was associated with

a cold, was clinically mild, and lasted less than 12 hours. He had

been asymptomatic in the interval between the 2 attacks.

Specifically there was no history of wet cough. Both parents were

non smokers.

Examination

� 75th percentile for weight and height, with evidence of

previous normal growth rate.

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PERSONAL PRACTICE

� Chest; no wheeze or crackles. A normal respiratory exami-

nation is common in children with viral wheeze and multi-trigger

wheeze. The absence of chest sings does not rule out structural

abnormalities or chronic conditions such as cystic fibrosis.

� Heart; no murmurs.

� Tonsils; moderately enlarged. A common finding in this age

group and, if not accompanied by evidence of severe upper

airway obstruction during sleep, is of no significance.

� Skin; possible minimal eczema on arm flexures. May indicate

an atopic tendency, but this does not increase the likelihood of

the multi-trigger wheeze phenotype.

Examination findings

These findings are compatible with the viral-wheeze phenotype

of preschool wheeze. If the hospital admission had been Alex’s

first attack, follow up is needed to determine wheeze phenotype.

Some children only have one attack, and follow up could

therefore depend on whether wheeze re-appears.

Investigations

There is no justification for doing any investigations. If Alex had

multi-trigger wheeze, a skin prick test to aeroallergens will

indicate whether he is atopic, but will not guide therapy since

there is no evidence that allergen avoidance (such as mattress

covers) measures are effective in this age group.

Treatment

Alex has no interval symptoms and regular therapy is not

required. Studies of regular inhaled corticosteroid in viral-trig-

gered wheeze have shown no clinical benefit. The outcome of

the viral-wheeze phenotype of wheeze should be explained to

his father i.e. that he is unlikely to have ‘‘allergic asthma’’, and

is likely to grow out of his tendency to wheeze with colds by 6

years of age. Since there has been one severe attack of wheeze, it

is reasonable to issue his father with a short acting beta2-agonist

(salbutamol) to be given via a large volume spacer and mask.

The normal dose of salbutamol is 4 to 6 puffs of salbutamol as

required to a maximum of 4 hourly. If the subsequent viral-

PAEDIATRICS AND CHILD HEALTH 20:4 187

wheeze attacks are clinically severe, a referral to a respiratory

paediatrician is advisable. Options available in secondary care

include; i) regular oral montelukast (which may reduce the

number, but not severity of wheeze attacks), and ii) intermittent

high dose inhaled steroids (which carries a risk of growth and

weight suppression). In the past, a short course of oral steroids

has been used to treat wheeze attacks in viral-wheeze pheno-

type. However, recent trials have found no benefit of oral

steroids in preschool children, either when given by parents, or

when given in hospital. If Alex had troublesome multi-trigger

wheeze, the British Thoracic Society Guideline recommends

starting regular low dose inhaled steroid (up to 400mg beclo-

metasone or equivalent a day). However, the threshold for

regular steroid steroids should be higher than older children and

should be accompanied by regular assessment of response. Long

acting beta2 agonists should not be used in children under

5 years of age.

Case outcome

Alex had 3 further episodes of wheeze, all triggered by colds,

over the subsequent 12 months. His parents were happy to treat

him at home, and by 3 years of age, his tendency to wheeze with

colds had resolved.

Differential

� Tracheomalacia

� Bronchitis

� Foreign body

� Cystic fibrosis

� Post-pertussis cough

� Primary ciliary dyskinesia

� Vascular ring (compressing the trachea)

� Aspiration (may be associated with gastro-oesophageal reflux

or H-type fistula)

� Tracheal polyps, or stenosis

� Congenital heart disease (e.g. atrial septal defect)

� Idiopathic pulmonary hypertension (very rare, but diagnosis

often delayed) A

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