Asthma and Allergic Disease in Asthma and Allergic Disease in ChildrenChildren

22ndnd Global View of Food Allergy MeetingGlobal View of Food Allergy Meeting NMIMRNMIMR

2727thth--2929thth March 2007March 2007

EOD EOD AddoAddo--YoboYobo FGCP MD MWACP FGCP MD MWACP MScMSc DTCH MB DTCH MB ChBChB

SMSSMS--KNUST/KATHKNUST/KATHKUMASI, GHANAKUMASI, GHANA

Overview of Asthma and AllergiesOverview of Asthma and AllergiesRecurrent disordersRecurrent disorders

Interferes with ability to enjoy life: school, play Interferes with ability to enjoy life: school, play activity, day to day functioning, productivity, sleep, activity, day to day functioning, productivity, sleep, psychosocial/family disturbances psychosocial/family disturbances

Apparent increasing prevalence and mortality in last Apparent increasing prevalence and mortality in last 2 decades2 decades

Consequent burden on health in developing Consequent burden on health in developing countries as ARI and other infectious diseases countries as ARI and other infectious diseases decreasedecrease

OutlineOutlineDefinitions:Definitions:

AsthmaAsthmaAllergyAllergy

PaediatricPaediatric considerations in asthma diagnosisconsiderations in asthma diagnosis–– Asthma reporting Asthma reporting vsvs asthma diagnosis problemsasthma diagnosis problems–– Similarities and differences in asthma in adults and childrenSimilarities and differences in asthma in adults and children

Prevalence of Asthma and allergy in developing Prevalence of Asthma and allergy in developing vsvs developed developed countries/Asthma reporting in the subcountries/Asthma reporting in the sub--regionregion

Ghanaian Asthma Studies:Ghanaian Asthma Studies:

Current trends in asthma and allergy prevalence Current trends in asthma and allergy prevalence

ChallengesChallenges

WHAT IS ASTHMA?WHAT IS ASTHMA?DIFFICULT!DIFFICULT! NO UNIVERSABLY ACCEPTED DEFINITIONNO UNIVERSABLY ACCEPTED DEFINITION

OFTEN ACCEPTABLE CLINICAL DEFINITION:OFTEN ACCEPTABLE CLINICAL DEFINITION:

““A chronic respiratory disorder characterized by A chronic respiratory disorder characterized by recurrent episodesrecurrent episodes of the symptoms of of the symptoms of coughcough, , dyspneoadyspneoa and and wheezewheeze, or a combination of these, , or a combination of these, which are which are reversible reversible either spontaneously or with either spontaneously or with treatmenttreatment””..

Diagnostic difficultiesDiagnostic difficulties““Not all that wheeze is asthmaNot all that wheeze is asthma””

Respiratory disordersRespiratory disorders mimicking asthmamimicking asthma•• Acute respiratory infections (young children), Acute respiratory infections (young children),

BronchiolitisBronchiolitis•• Wheezy bronchitisWheezy bronchitis

Nocturnal or post exercise cough in children Nocturnal or post exercise cough in children (may be diagnosed as asthma)(may be diagnosed as asthma) chronic bronchitis, emphysema (adults)chronic bronchitis, emphysema (adults)

““Not all asthma wheezesNot all asthma wheezes””

Other Conditions presenting with Other Conditions presenting with AsthmaAsthma--like symptoms:like symptoms:

Foreign body inhalationForeign body inhalationBronchiolitisBronchiolitisImmune deficiency diseaseImmune deficiency diseaseHypersensitivity Hypersensitivity pneumonitispneumonitisLoefflerLoeffler--like syndromes commonly like syndromes commonly with with ascariasisascariasis and and strongylodiasisstrongylodiasisAspergillosisAspergillosisChronic aspiration due to Chronic aspiration due to swallowing disorder swallowing disorder –– GERD GERD (GORD)(GORD)

Salient features in AsthmaSalient features in AsthmaCHRONIC DIFFUSE OBSTRUCTIVE AIRWAYS CHRONIC DIFFUSE OBSTRUCTIVE AIRWAYS

Cough Cough ±±

wheezing and tightness in the chest wheezing and tightness in the chest /breathlessness/breathlessness

INFLAMMATIONINFLAMMATION ((AtopicAtopic/immunologic) A key association/immunologic) A key association

AIRWAY HYPERAIRWAY HYPER--REACTIVITYREACTIVITY ((airway narrowing in a patient with asthma in response to stimulus that is innocuous in an otherwise normal person))

REVERSIBILITY OF SYMPTOMSREVERSIBILITY OF SYMPTOMS ((Relief Relief –– spontaneous/bronchodilators)spontaneous/bronchodilators)

OTHER ASTHMA DEFINITIONSOTHER ASTHMA DEFINITIONSBASED ON AIRWAY HYPERBASED ON AIRWAY HYPER-- RESPONSIVENESSRESPONSIVENESS

BASED ON EXERCISE CHALLENGESBASED ON EXERCISE CHALLENGES

Allergy & Allergy & AtopyAtopyA condition in which the body has an exaggerated A condition in which the body has an exaggerated (adverse) immunological response (involving the production (adverse) immunological response (involving the production large amounts of large amounts of IgEIgE) to an substance (e.g. food or drug). ) to an substance (e.g. food or drug). Also described as hypersensitivity.Also described as hypersensitivity.

AtopyAtopy is defined as the tendency to develop is defined as the tendency to develop IgEIgE antibodies antibodies to commonly encountered environmental allergens by to commonly encountered environmental allergens by natural exposure, in which the route of entry of allergen is natural exposure, in which the route of entry of allergen is across intact mucosal surfaces [Pepys, 1975]. across intact mucosal surfaces [Pepys, 1975].

In prevalence studies in random populations:In prevalence studies in random populations: AtopyAtopy = the presence of one or more positive skin= the presence of one or more positive skin--prick prick tests response to a number of common allergens in the tests response to a number of common allergens in the environment. [environment. [DolovichDolovich, 1983], 1983]

OPERATIONAL DEFINITION OF ASTHMAOPERATIONAL DEFINITION OF ASTHMA (GINA 2006)(GINA 2006)

Asthma is a chronic inflammatory disorder of the airwaysin which many cells and cellular elements play a role.The chronic inflammation is associated with airwayhyperresponsiveness that leads to recurrent episodes ofwheezing, breathlessness, chest tightness, and coughing,particularly at night or in the early morning. Theseepisodes are usually associated with widespread, butvariable, airflow obstruction within the lung that is oftenreversible either spontaneously or with treatment.

ASTHMA PREVALENCEASTHMA PREVALENCEGlobal Asthma prevalence: 1% to 18% Lower values in developing countries

Evidence of Increasing Asthma prevalence in some countries (Taiwan, Hong Kong, Spain, Ghana)

Stabilized asthma prevalence in other countries (Thailand, Spanish adolescents)

Challenges with Childhood Asthma & Allergy Challenges with Childhood Asthma & Allergy Diagnosis and Reporting in Developing CountriesDiagnosis and Reporting in Developing Countries

Diagnoses and Treatment based on symptomsDiagnoses and Treatment based on symptomsLanguage difficulties with symptoms e.g. Language difficulties with symptoms e.g. ““wheezewheeze””, , ““tightness in chesttightness in chest””Frequent respiratory tract infection mimicking Frequent respiratory tract infection mimicking asthma (viral infections with wheeze)asthma (viral infections with wheeze)Relatively high incidence other differential Relatively high incidence other differential diagnosesdiagnoses (tendency for misdiagnosis)(tendency for misdiagnosis)Inadequate clinical evaluationInadequate clinical evaluationFew and Irregular clinic visits (Few and Irregular clinic visits (Complacency)Complacency)Poor patient followPoor patient follow--up & documentation systemsup & documentation systems?Stigma?Stigma

CAUTION ON [RETROSPECTIVE] HOSPITAL CAUTION ON [RETROSPECTIVE] HOSPITAL DERIVED DATADERIVED DATA

Asthma and Asthma and AtopyAtopy PrevalencesPrevalences in Kumasi, Ghana:in Kumasi, Ghana:

Inferences from Exercise test and Inferences from Exercise test and Skin Test responsesSkin Test responses--Two studies Two studies

10 years apart (1993, 2003)10 years apart (1993, 2003)

0.0%1.0%2.0%3.0%4.0%5.0%6.0%7.0%8.0%9.0%

Urban Rich

Urban PoorRural

Whole group

School category

Prevalence of EIB in 9-16 year old Ghanaian School children 10 years apart (1993 - 2003)

1993 (N=1095)2003 (N=1877)

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

Urban Rich (n=401) Urban poor (n=436) Rural (n=447)

Asthma prevalence by questionnaire among 9-16 year old Kumasi school children - 2003

ProbableCertain

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

40.0%

Urban Rich Urban Poor Rural Whole group

Prevalence of positive skin test responses among 9-12 year old Ghanaian school children - 10 years apart (1993-2003)

19932003; p=0.000

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

Urban Rich Urban Poor Rural Whole group

Sensitisation to common panel allergens (df, dp, cat, dog)

19932003

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0% d

f

dp

cat

dog d

f

dp

cat

dog d

f

dp

cat

dog d

f

dp

cat

dog

Whole group UR UP R

Changes in prevalence of positive skin test responses for specific allergens among schools

1993 (N=916)2003 (N=1862)

EIB and EIB and AtopyAtopy

Proportion of EIB positive persons with atopy

1993 2003

10% (3/30) 35% (33/95)

Other Epidemiological Other Epidemiological ObservationsObservations

Age of onset of asthma symptoms among Age of onset of asthma symptoms among Kumasi school children (9 Kumasi school children (9 –– 15 yrs) (1993)15 yrs) (1993)

0%

5%

10%

15%

20%

25%

30%

1 yr 3 yrs 5yrs 7yrs 9yrs 11yrs 16yrs

% Respondents

0

10

20

30

40

50

60

1st yr 2nd yr 3rd yr 4th yr 5th yr 6-10th yr After10th yr

Onset of wheeze among 9-15 year-old Asthmatic School Children, Kumasi, 2003

% R

espo

nden

ts

Severity of asthma:Severity of asthma:Most children have mild to Most children have mild to moderately severe asthmamoderately severe asthma

Kumasi: Mostly mildKumasi: Mostly mild

? One reason for apparently low ? One reason for apparently low prevalence figures in Ghanaprevalence figures in Ghana

Associated phenomena:Associated phenomena:Strong association with allergic Strong association with allergic phenomena phenomena -- rhinitis, eczema in rhinitis, eczema in Western countriesWestern countries

Poor association with eczema in Poor association with eczema in African countriesAfrican countries

Prevalence of histories of eczema, rhinitis and known allergies among Ghanaian asthmatic and non-

asthmatic children (1997)

0%

10%

20%

30%

40%

50%

60%

70%

80%

Eczema Rhinitis Urticaria Known allergies

Cases

Controls

(n=50)

(n=50)

(6)(10)

(36)

(25)

(28) (26)

(7)

(16)

(p=0.41) (p=0.007) (p=0.82) (p=0.07)

0%

10%

20%

30%

40%

50%

60%

Eczema Allergic Rh Urticaria Known Allergies

Histories of Eczema, Allergic Rhinitis, Urticaria and Known Allergies among 9-13 year old Asthmatics and Non Asthmatic School Children,

Kumasi, 2003

2003 Asthma (N=87)2003 Non-Asthma (N=94)

(19)(13)

(49)

(28)(21)

(6)

(16)

(8)

(p=0.328) (p=0.000) (p=0.001) (p=0.041)

Risk factors for childhood asthma in Kumasi:Risk factors for childhood asthma in Kumasi:

Exposure and sensitisation to Exposure and sensitisation to (indoor )allergens especially, (indoor )allergens especially, HDMsHDMsFamily history Family history ((““Asthma in familyAsthma in family””))Tobacco Smoke ExposureTobacco Smoke ExposureArea of residence Area of residence

Urban Urban vrsvrs Rural Rural Kumasi data: Kumasi data: UP 1.4%; UR 4.2%; R2.2%; Overall 3.1%UP 1.4%; UR 4.2%; R2.2%; Overall 3.1%

(Thorax, 1997; 52: 161(Thorax, 1997; 52: 161--165)165)

Inner city residenceInner city residenceSmall household sizeSmall household sizePosition in Position in sibshipsibship (<5)(<5)

Ref: AddoRef: Addo--Yobo et al, Yobo et al, J.AllergyJ.Allergy ClinClin ImmunolImmunol, 2001;106:363, 2001;106:363--368368

TemaTema School Children StudySchool Children Study--11 AdjeiAdjei ND, AddoND, Addo--Yobo EODYobo EOD

Schools:Schools: TemaTema Parents JSS and Parents JSS and TemaTema ManheanManhean JSSJSS

Key Questions:Key Questions:Have you wheezed in the last twelve months? Have you wheezed in the last twelve months? Do you have coughs in the mornings or evenings Do you have coughs in the mornings or evenings when you do not have a cold?when you do not have a cold?Do you wheeze or have tightness in the chest Do you wheeze or have tightness in the chest with or after exercise?with or after exercise?Are symptoms on and off?Are symptoms on and off?Doctor diagnosis of asthmaDoctor diagnosis of asthmaUse of appropriate medicationUse of appropriate medication

TemaTema School Children Study School Children Study --22 AdjeiAdjei ND, AddoND, Addo--Yobo EODYobo EOD

4.8% (23/484) have asthma by study criteria and doctor4.8% (23/484) have asthma by study criteria and doctor-- diagnosed diagnosed (certain diagnosis)(certain diagnosis)

11 from 11 from TemaTema ManheanManhean JSS (D) JSS (D) 12 from 12 from TemaTema ParentsParents’’ Association JSS (T).Association JSS (T).

4.1% (20/484) doctor4.1% (20/484) doctor--diagnosed but not asthmatic by diagnosed but not asthmatic by study criteria study criteria (Wrong diagnosis).(Wrong diagnosis).

7.4% (36/484) asthmatic by study criteria but not doctor7.4% (36/484) asthmatic by study criteria but not doctor-- diagnosed diagnosed (missed diagnosis).(missed diagnosis).

83.7% (405/484) 83.7% (405/484) nonnon--asthmaticsasthmatics (neither by criteria nor (neither by criteria nor doctordoctor--diagnosis)diagnosis) i.e. Asthma prevalence of 16.3% (79/484)i.e. Asthma prevalence of 16.3% (79/484)

Insignificant differences between the 2 populationsInsignificant differences between the 2 populations

TemaTema School Children Study School Children Study --33 AdjeiAdjei ND, AddoND, Addo--Yobo EODYobo EOD

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

Conventional

Non-ConventionalTraditional

Nothing

Forms of asthma therapy used among Tema school children

Proportion

Other Observations from Other Observations from studiesstudies

Majority (90% or more) had mild Majority (90% or more) had mild symptomssymptomsMajority of symptomatic subjects were Majority of symptomatic subjects were both EIB positive and both EIB positive and AtopicAtopicAtopyAtopy was more common in the younger was more common in the younger (<12 yrs) than older children(<12 yrs) than older childrenThe most common form of sensitisation is The most common form of sensitisation is to House dust mites to House dust mites (D. (D. farinaefarinae, D. , D. PteronyssinusPteronyssinus))

Conclusions from Studies:Conclusions from Studies:Asthma is not uncommon in GhanaAsthma is not uncommon in GhanaChildhood asthma is commonChildhood asthma is commonMost sufferers may have mild symptomsMost sufferers may have mild symptomsAtopyAtopy is an important basis for asthma symptoms is an important basis for asthma symptoms in Ghana.in Ghana.Asthma and Asthma and atopyatopy prevalence are increasing in prevalence are increasing in Ghana.Ghana.Urbanisation/affluence is a high risk factor for Urbanisation/affluence is a high risk factor for asthmaasthmaLow level of patientLow level of patient--physician awarenessphysician awareness (teamwork deficit)(teamwork deficit)High proportion of undiagnosed (poorly High proportion of undiagnosed (poorly managed) subjectsmanaged) subjectsWrong asthma labels probably not uncommonWrong asthma labels probably not uncommon

Possible reasons for Increased Possible reasons for Increased Asthma prevalence in KumasiAsthma prevalence in Kumasi

Lifestyles Lifestyles –– ?Increased exposure to allergens?Increased exposure to allergens–– More fluffy upholstery More fluffy upholstery -- carpets (+ carpets (+ HDMsHDMs))–– indoor lifeindoor life–– Introduction of blankets in PNGIntroduction of blankets in PNG–– ?Poor exercise?Poor exercise–– ??ImmunisationImmunisation (Measles in PNG)(Measles in PNG)

DietDietInfectionsInfectionsRole of Role of HelminthicHelminthic infestation/worm treatmentinfestation/worm treatmentFamily historyFamily history

ConclusionsConclusionsChanging Childhood asthma Epidemiology Changing Childhood asthma Epidemiology in Ghana.in Ghana.–– Asthma is commoner in Ghanaian ChildrenAsthma is commoner in Ghanaian Children–– AtopicAtopic asthma is more commonasthma is more common–– Urbanisation seems important risk factorUrbanisation seems important risk factor

ABC: Asthma Begins In ChildhoodABC: Asthma Begins In Childhood Vigilance in diagnosis and managementVigilance in diagnosis and management

Need for more Asthma Clinics in health Need for more Asthma Clinics in health institutions in very near futureinstitutions in very near future

The role of (Paediatric) Asthma ClinicsThe role of (Paediatric) Asthma ClinicsEarly appropriate diagnosisEarly appropriate diagnosisCounselling Counselling –– Controlling attacks Controlling attacks -- appropriate medications and appropriate medications and appropriate use of medicationsappropriate use of medicationsMonitoring of clinical responseMonitoring of clinical response Respiratory effortRespiratory effort--Peak flow rates/Peak flow rates/SpirometrySpirometry Symptom frequency Symptom frequency

–– Towards symptomTowards symptom--free lifefree lifeIdentifying and managing concurrent/Identifying and managing concurrent/intercurrentintercurrent illnesses (illnesses (esp.HIVesp.HIV situation)situation)Drug availabilityDrug availability

““Life made easy for the Adult PhysicianLife made easy for the Adult Physician””

ReferencesReferencesAddoAddo--YoboYobo EO, Woodcock A, EO, Woodcock A, AlloteyAllotey A, A, BaffoeBaffoe--Bonnie B, Bonnie B, StrachanStrachan D, D, CustovicCustovic A. A. ExerciseExercise--induced induced bronchospasmbronchospasm and and atopyatopy in Ghana: in Ghana: two surveys ten years apart. two surveys ten years apart. PLoSPLoS Med. 2007 Feb;4(2):e70.Med. 2007 Feb;4(2):e70.

AddoAddo--YoboYobo EO, EO, CustovicCustovic A, Taggart SC, A, Taggart SC, AsafoAsafo--AgyeiAgyei AP, Woodcock A. AP, Woodcock A. ExerciseExercise--induced induced bronchospasmbronchospasm in Ghanain Ghana: differences between : differences between urban and rural school children. Thorax. 1997 Feb; 52(2): 161urban and rural school children. Thorax. 1997 Feb; 52(2): 161--5.5.

AddoAddo--YoboYobo EO, EO, CustovicCustovic A, Taggart SC, Craven M, A, Taggart SC, Craven M, BaffoeBaffoe--Bonnie B, Bonnie B, Woodcock A. Woodcock A. Risk factors for asthma in Ghana.Risk factors for asthma in Ghana. Journal of Allergy and Clinical Immunology. 2001; Journal of Allergy and Clinical Immunology. 2001; VolVol 108, Number 3, 108, Number 3, 363 363 –– 368.368.

Woodcock A , Woodcock A , AddoAddo--YoboYobo EO, Taggart SC, Craven M, EO, Taggart SC, Craven M, CustovicCustovic A. A. Pet allergen levels in homes in Ghana and the United KingdomPet allergen levels in homes in Ghana and the United Kingdom. . Journal of Allergy and Clinical Immunology. 2001; Journal of Allergy and Clinical Immunology. 2001; VolVol 108, Number 3, 108, Number 3, 463 463 –– 465.465.

AddoAddo--YoboYobo EO, EO, CustovicCustovic A, Taggart SC, A, Taggart SC, AsafoAsafo--AgyeiAgyei AP, Woodcock A. AP, Woodcock A. Seasonal variability in exercise test responses in Ghana.Seasonal variability in exercise test responses in Ghana. Paediatric Allergy and Immunology 2002: 13: 303 Paediatric Allergy and Immunology 2002: 13: 303 –– 306.306.