Childhood asthmaChildhood asthma

Rod Addis, Vanessa KeraiRod Addis, Vanessa Kerai

OverviewOverview

• PrevalencePrevalence

• AetiologyAetiology

• PathophysiologyPathophysiology

• Clinical featuresClinical features

• DiagnosisDiagnosis

• Management <5sManagement <5s

• Management 5-12Management 5-12

PrevalencePrevalence

• Asthma is commonest in children - Asthma is commonest in children - predominantly extrinsic.predominantly extrinsic.

• Childhood asthma affects up to 5% of Childhood asthma affects up to 5% of childrenchildren

• Peak age of onset is 5 years. Peak age of onset is 5 years. • More common in boys than girls (3:2)More common in boys than girls (3:2)• 25% of asthmatic children have some 25% of asthmatic children have some

restriction of physical activity.restriction of physical activity.

AetiologyAetiology

• Genetic predisposition - atopy is known to be Genetic predisposition - atopy is known to be inherited by a dominant gene on chromosome 11:inherited by a dominant gene on chromosome 11:– Atopic component in 40% of patientsAtopic component in 40% of patients– Associated with eczema, fever or urticaria. Associated with eczema, fever or urticaria. – Raised IgE, eosinophilia, labile PEFR, known sensitivity to Raised IgE, eosinophilia, labile PEFR, known sensitivity to

allergensallergens• Infection:Infection:

– Viral-induced wheeze occurs in some 20% of childrenViral-induced wheeze occurs in some 20% of children– acute RSV bronchiolitis can cause a persistent asthma acute RSV bronchiolitis can cause a persistent asthma

syndrome independent of a familial atopy or asthmasyndrome independent of a familial atopy or asthma• Passive smokingPassive smoking• Bronchial hyper-responsivenessBronchial hyper-responsiveness

Disease Disease progression/remissionprogression/remission• In cases where episodes of asthma are In cases where episodes of asthma are

infrequent, asthma will cease in adult lifeinfrequent, asthma will cease in adult life

• Patients with frequent episodes of asthma or Patients with frequent episodes of asthma or chronic asthma are more likely to suffer from life-chronic asthma are more likely to suffer from life-long asthmalong asthma

• Risk factors for persisting asthma:Risk factors for persisting asthma:– early age of onset and requiring frequent periods of early age of onset and requiring frequent periods of

hospital treatmenthospital treatment– patients with ongoing eczemapatients with ongoing eczema– patients with chronic lung abnormalitiespatients with chronic lung abnormalities– smoking with asthmasmoking with asthma

PathophysiologyPathophysiology

• Acute phase (minutes)Acute phase (minutes)– Bronchoconstriction (contraction of bronchial Bronchoconstriction (contraction of bronchial

smooth muscle)smooth muscle)

• Late phase (mediated by mast cells and Late phase (mediated by mast cells and marcrophages + recruitment of further marcrophages + recruitment of further immune cells increasing inflammatory immune cells increasing inflammatory reaction)reaction)– Mucosal oedemaMucosal oedema– Increased secretion of mucusIncreased secretion of mucus

Clinical featuresClinical features

• Symptoms of an acute Symptoms of an acute attack:attack:– expiratory wheeze expiratory wheeze – SOBSOB– sometimes cough may be the sometimes cough may be the

only symptomonly symptom– symptoms worse at nightsymptoms worse at night– most patients may feel chest most patients may feel chest

tightness in the morningtightness in the morning– young children may vomit or young children may vomit or

have reduced appetitehave reduced appetite

• Signs of an acute attack:Signs of an acute attack:– child unable speak or to child unable speak or to

walk due to walk due to breathlessnessbreathlessness

– intercostal recession and intercostal recession and use of accessory musclesuse of accessory muscles

– exhaustedexhausted– wheeze with tachypnoea wheeze with tachypnoea

and tachycardiaand tachycardia– silent chest (severe silent chest (severe

presentation)presentation)

• Between attacks, the child may be asymptomatic

• Peak flow - not reliable due to poor technique• Chronic asthmatic may have a Harrison's sulcus

DiagnosisDiagnosis**BTS/SIGN (May 2008). British Guideline on the Management of AsthmaBTS/SIGN (May 2008). British Guideline on the Management of Asthma • Clinical features that Clinical features that

increase the probability of increase the probability of asthma:asthma:– More than one of the following More than one of the following

symptoms especially if frequent, symptoms especially if frequent, worse at night/early worse at night/early morning/after exercise/exposure morning/after exercise/exposure to triggers etc.to triggers etc.

• WheezeWheeze• CoughCough• difficulty breathing, difficulty breathing, • chest tightness chest tightness

• Atopic disorder Atopic disorder • FH of atopic disorder/asthma FH of atopic disorder/asthma • Improvement in symptoms or Improvement in symptoms or

lung function with adequate lung function with adequate therapy therapy

• Clinical features that lower Clinical features that lower the probability of asthma:the probability of asthma:– Symptoms with URTI onlySymptoms with URTI only– no interval symptoms no interval symptoms – isolated cough in the absence isolated cough in the absence

of wheeze or difficulty breathing of wheeze or difficulty breathing – history of moist cough history of moist cough – prominent dizziness, light-prominent dizziness, light-

headedness, peripheral tingling headedness, peripheral tingling – repeatedly normal physical repeatedly normal physical

examination of chest when examination of chest when symptomatic symptomatic

– normal PEFR/spirometry when normal PEFR/spirometry when symptomatic symptomatic

– no response to a trial of asthma no response to a trial of asthma therapy therapy

– clinical features pointing to clinical features pointing to alternative diagnosis alternative diagnosis

Diagnosis IIDiagnosis IIhigh probability of asthma:high probability of asthma:

– start a trial of treatment start a trial of treatment – review and assess response review and assess response

• reserve further testing for reserve further testing for those with a poor response those with a poor response

  

• low probability of asthmalow probability of asthma– consider more detailed consider more detailed

investigation and specialist investigation and specialist referralreferral

• intermediate probability intermediate probability of asthmaof asthma– if there is significant if there is significant

reversibility/if treatment reversibility/if treatment trial is beneficial asthma trial is beneficial asthma is probable is probable • Treat as asthma, but aim Treat as asthma, but aim

to find the minimum to find the minimum effective dose of therapy.effective dose of therapy.

• At a later point, consider At a later point, consider a trial of reduction, or a trial of reduction, or withdrawal, of treatment withdrawal, of treatment

– if there is no significant if there is no significant reversibility, and reversibility, and treatment trial is not treatment trial is not beneficial, consider tests beneficial, consider tests for alternative conditionsfor alternative conditions

Non-drug measuresNon-drug measures

Avoiding house dust mitesAvoiding house dust mites

• Methods to reduce levels of house dust mites Methods to reduce levels of house dust mites have not been proved to reduce symptoms of have not been proved to reduce symptoms of asthma.asthma.

Avoidance of other Avoidance of other exacerbating factorsexacerbating factors

• No evidence confirms that removing pets No evidence confirms that removing pets from the house helps children with asthma from the house helps children with asthma who have a pet allergy, but many experts who have a pet allergy, but many experts still recommend this approach. still recommend this approach.

• Cessation of smoking by parents can Cessation of smoking by parents can reduce the severity of their children's reduce the severity of their children's asthma.asthma.

Control of asthma is assessed against Control of asthma is assessed against these standards:these standards:

• Minimal symptoms during day and nightMinimal symptoms during day and night

• Minimal need for reliever drugsMinimal need for reliever drugs

• No exacerbationsNo exacerbations

• No limitation of physical activityNo limitation of physical activity

• Normal lung function (FEV1 or PEF >80% Normal lung function (FEV1 or PEF >80% predicted or best, or both).predicted or best, or both).

A stepwise approach aims to:A stepwise approach aims to:

• Abolish symptoms as soon as possibleAbolish symptoms as soon as possible

• Optimise peak flow by starting treatment Optimise peak flow by starting treatment at the level most likely to achieve thisat the level most likely to achieve this..

Management <5Management <5Step 1• SABA

Step 2• Inhaled steroids if:

– exacerbation of asthma in the last 2 years requiring oral steroids

– using inhaled β2 agonists three times a week or more – symptomatic three times a week or more – waking one night a week

*Titrate steroid dose to lowest dose at which effective treatment maintained

• Leukotriene agonists if inhaled steroids not tolerated

Management <5Management <5

Step 3• If taking inhaled steroid, add in leukotriene

antagonist• If taking leukotriene antagonist, add inhaled steroid• If <2 proceed to Step 4

Step 4• Refer to respiratory paediatrician

Management 5-12Management 5-12Step 1• SABA

• Step 2• Inhaled steroids if:

– exacerbation of asthma in the last 2 years requiring oral steroids

– using inhaled β2 agonists three times a week or more – symptomatic three times a week or more – waking one night a week *Titrate steroid dose to lowest dose at which effective treatment

maintained

– Leukotriene agonists if inhaled steroids not tolerated

Management 5-12Management 5-12Step 3• Add in LABA

– good response • continue LABA

– if there is benefit from LABA but control is still inadequate• continue LABA• increase inhaled steroid dose• if control still inadequate then go to step 4

– if no response to LABA• stop LABA• increase inhaled steroid • If control is still inadequate trial of other therapies:

– leukotriene receptor antagonist– SR theophylline

– If control still inadequate then go to step 4

Management 5-12Management 5-12Step 4• Increase dose of inhaled steroid

Step 5• Daily oral steroid (lowest dose which provides control)• Maintain high inhaled steroid• Respiratory peadiatrician r/v* Patients on long term steroid tablets >3/12 or requiring frequent

courses of steroid tablets (3-4/yr) are at risk of systemic side effects. Monitor for general side effects of steroid use + specific monitoring of growth and screening for the development of cataracts

When to refer?When to refer?

• Diagnostic uncertaintyDiagnostic uncertainty

• Symptoms present from birthSymptoms present from birth

• Excessive vomiting or possetingExcessive vomiting or posseting

• Severe URTISevere URTI

• Persistent wet coughPersistent wet cough

• Growth falteringGrowth faltering

• Family history of unusual chest diseaseFamily history of unusual chest disease

• Unexpected clinical findings (e.g focal chest signs or Unexpected clinical findings (e.g focal chest signs or dysphagia)dysphagia)

• Failure to respond to conventional treatmentFailure to respond to conventional treatment

• Parental anxiety.Parental anxiety.

Questions?Questions?

Thank youThank you