Transcript The spectrum of allergic diseases

The spectrum of allergic diseases
Hugo Van Bever
Department of Pediatrics
National University Singapore
APAPARI workshop – Hanoi, Vietnam – May 2008
skyline
HDB flat
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Clean - well organized - tropical
High prevalence of allergic diseases
A lot of HDMs (Blomia tropicalis)
Strange food allergies (bird nest, etc…)
Pediatric Allergy in Asia (APAPARI)
Starting 1998
HR Lee
SI Lee
Morikawa
Chen
KH Hseih
JL Huang
P Vichyanond
A Tam G Wong
J Debruyn
BW Lee
H Van Bever
S Siregar
M Bautista
APAPARI – JACIN MEETING, JAKARTA – APRIL 2006
APAPARI - Education
1. Joint meetings with Allergy Societies
- 2002: Japan (Tokyo)
- 2003:Singapore (workshop)
- 2004: Hong Kong (IPRAIC)
- 2005: S-Korea (Seoul)
- 2006: Indonesia (Jakarta)
- 2007: Philippines (Manila) & WAO (Bangkok)
- 2008: Singapore (SPS – Oct 2008)
2. Training courses on pediatric allergy
- 2006: Jakarta (Indonesia) / Balikpapan (Borneo)
- 2007: Phom Penh (Cambodia) / Jakarta / Ho Chi Minh (Vietnam)
- 2008: Hanoi (Vietnam)
Vietnamese studies on paediatric allergy
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ISAAC-based asthma and atopic symptoms among Hanoi school children. Nga
NN et al. Pediatr Allergy Immunol 2003, 14, 272-9.
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Obesity is associated with increased risk of allergy in Vietnamese adolescents.
Irei V et al. Eur J Clin Nutr 2005, 59, 571-7.
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Poor sanitation and helminth infection protect against skin sensitization in
Vietnamese children: a cross-sectional study. Flohr C, et val. J Allergy Clin
Immunol 2006, 118, 1305 – 11.
-
Prevalence of asthma and asthma-like symptoms in Dalat Highlands, Vietnam.
Sing Med J 2007, 48, 294 – 303.
ISAAC-based asthma and atopic symptoms among
Hanoi school children. Nga NN et al. Pediatr Allergy
Immunol 2003, 14, 272-9.
- Hanoi
-cross-sectional study
-5 -11 year-old
-Response rate 66.4%
- 969 responders
Cumulative prevalence of asthma, rhinitis and
eczema in Singaporean children.
1 - 2 yrs-old
2002 -2003
4 - 6 yrs-old
2000
6 – 7 yrs-old
2001
12 – 15 yr-old
2001
Increase in prevalence of allergic diseases
changes in the environment
Induction of the expression of allergy
HYGIENE HYPOTHESIS
- asthma
- rhinitis
- eczema
Allergy = a feature and NOT a
disease !
= … the ability to produce specific antibodies
(IgE) to different substances of the
environment (inhalant and food allergens)…
IgE
inflammation
shock organs
= swelling - narrowing
symptoms
Allergic diseases …
eczema
healthy
enteritis
asthma
ALLERGY
rhinitis
urticaria
conjunctivitis
migraine
Positive skin tests in 273 HEALTHY children at the age
6-7 years (Belgium - 1996).
ALLERGEN
n
%
- HDM
21
8%
- Cat dander
6
2%
- Birch pollen
1
0%
- Grass pollen
8
3%
- ANY
29
11 %
Allergy, one feature with many faces
AIRWAYS
SKIN
Allergic diseases …
mild to … severe
“ The Allergic March “
Environmental substances
= allergens (proteins…)
1. Inhalant allergens
house dust mites, pollen
pets, moulds
2. Food allergens
egg, cow’s milk, soy, wheat
peanuts, fish, shrimp, etc…
( < 3 yrs)
(> 3 yrs)
Contact with food allergens
 eating – drinking
 touching
 smelling
 breast milk - prenatal
Food allergens in house dust.
Witteman AM, van Leeuwen J, van der Zee J, Aalberse RC.
Int Arch Allergy Immunol. 1995 Aug;107(4):566-8.
microgr/g dust
10
1
0.1
0.01
ovomucoid
b-lactoglobulin
The amount of ovomucoid and b-lactoglobulin in 11 house dust samples
0.073 microg/g dust = detection limit ovomucoid
0.016 microg/g dust = detection limit b-lactoglobulin
“ Kiss of death “
 5% of adults with food allergy
 Foods: peanuts, nuts, apple, pea, fish
 Relationship: husband, boyfriend, etc.
Hallett et al, NEJM 2002, 346, 1833
House Dust Mites
Blomia tropicalis
Dermatophagoides farinae
Asthma
Rhinitis
Eczema
House Dust Mites in Singapore
• High temp and humidity provides perfect
environment for HDMs
• High counts (> 100 mites/g dust) of HDM are isolated
in Singapore
• A wide variety of mite species is isolated other than
Dermatophagoides.
• Blomia tropicalis is predominant.
Mite Species Present in Singaporean Mattresses
Species
B. tropicalis
D. pteronyssinus
S .brasiliensis
T. granarius
D. farinae
A. malaysiensis
C. malaccensis
M. intermedius
% (n = 50)
94
80
84
44
26
20
24
12
Chew FT 1999 Clin Exp Allergy 29:201-206
Allergic diseases
1. GENETIC CONSTITUTION
2. ENVIRONMENT
- Prenatal (pregnancy)
- Postnatal (first months of life)
Genetic constitution
Parents
1. both are negative
2. mother negative – father positive
3. mother positive – father negative
4. both positive
5. both strongly positive
Risk
18 %
40 %
50 %
70 %
90 %
Allergic diseases
1. GENETIC CONSTITUTION
2. ENVIRONMENT
- Prenatal (pregnancy)
- Postnatal (first months of life)
Direction of immune responses in early life
allergic profile (Th2 predominance)
Allergic (Th2)
Birth
Factors
1. constitution
2. bacterial load
3. allergen exposure
Non-allergic (Th1)
ATOPY = inbalance
Th1
Th2
Th3
regulatory T cells
IL-10, TGF-b
T helper lymphocytes
Modified from S. Romagnani CEA, 36, 1357–1366
Roles of T cells
/ Allergic disease
Orihara, Kanami et al., WAO 2008
Postnatal immune deviation from allergic
(Th2) to non-allergic (Th1)
POSITIVE
1. Increased bacterial load
- family size, farming
- day care attendance
- probiotics (Lactobacillus sp.) prebiotics, etc.
2. Tolerance through high exposure to allergens
(pets – other allergens)
NEGATIVE
1.House dust mite – pollen (low doses)
2. RSV
3. Pollution (DEPs – cigarette)
4. Antibiotics - paracetamol
Diagnosis of allergy
1. History
2. Clinical examination
3. SPT = golden standard !
4. Specific IgE
5. Other lab tests: ECP, cytokines, etc…
6. eNO
7. Allergen provocation test
(nasal, bronchial, etc…)
Unproven diagnostic tests for allergy…
- IgG
 against everything you can dream
- Electrodermal tests
(“ Bioreasonance tests “)
- Other “witchcraft”
(“ Kinesiology ”)
APPLIED KINESIOLOGY
Skin prick testing
= golden standard for diagnosing
allergy in children & adults