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Food allergy in children
Hugo Van Bever
Department of Pediatrics
National University Singapore
APAPARI Workshop, Hanoi, May 2008
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Food Allergy
Fact or Fiction?
1. Difficult problem group of diseases
2. Lot of non-scientific data opinions truths tradition
stories.
3. Food other types of reaction (intolerance,intoxication, etc)
4. Too many children are labeled as being food-allergic
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Adverse reactions to food
Food intolerance (most common)
Food allergy (hypersensitivity)
Food aversion (phobia)
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FOOD INTOLERANCE
- toxins
- infections
- pharmacological properties of food
- host factors (lactase deficiency)
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Food allergy= an immunologically-mediated reaction
against food
1. IgE-mediated
Others (less evidence)2. Cell-mediated reactions
(T lymphocytes - delayed onset)
3. Mixed types (atopic dermatitis)
4. Other mechanisms
( unknown - CICcomplementetc)
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Prevalence of food allergy
1. General population: 2 %
2. Young children (< 3 yrs): 8 %
3. Singapore children: 4 5 %
SPECIFIC GROUPS
4. Young children with severe eczema: 90 %
5. Children with asthma: < 10 %
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Manifestations of food allergy
1. SKIN: urticaria angioedema > eczema
2. RESPIRATORY: rhinitis asthma
3. GI TRACT: diarrhea vomiting FTT- eosinophilic gastroenteritis
- enterocolitis
4. GENERAL: anaphylactic shock5. OTHER: migraine, hyperactivity,
sleep disturbances etc ?
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Foods triggering anaphylaxis in
Singaporean children (1992 1996)
124 children with acute anaphylaxis at NUH
mean age (yrs)
1. Egg and milk 11 % 0.7
2. Birds nest 27 % 4.5
3. Chinese herbs 7 % 5.0
4. Crustacean seafood 24 % 11.0
5. Others * 30 % 7.0
* Chicken, duck, ham, fruits (banana, rambutan), cereals, gelatin and spices
Goh et al. Allergy 54, 1999, 78-92.
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Common culprits - Singapore children
Infants: cows milk
hen's egg
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Common culprits - Singapore children
Older children
seafood (shellfish), birds nest,
Chinese herbs, eggs
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FISHSweden 39% of food-
allergic children are
allergic to cod
Uncommon in Singapore
- per capita consumption of 25.05kg
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Every food has its own story
cows milk
hens egg
peanuts, fish, seafood,
prevalence
age
3 yrs 5 yrs6 months
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Sensitization to food
sensitization to allergens
1. prenatal sensitization
2. postnatal sensitization
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Sensitization to food
eating, touching and
smelling
peanuts
fish
hens egg
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Allergy to cows milk proteins in mothers
milk or in hydrolyzed cows milk infant
formulas assessed by intestinal permeabilitymeasurements.
Barau E et al.Allergy 1994; 49:295-8.
ovalbumin
peanut protein
cows milk protein
mothers milk
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Case
9 month old boy
Totally breastfed
1st introduction of CM formula
One minute after the first bite
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Prenatal sensitization to
allergensdoes it exist?
1. clinical evidence
(peanuts ovalbumine pollen house
dust mite cat - dog)
2. allergens in amniotic fluid & cord blood
3. active transport through placenta
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Allergic sensitization during pregnancy influences the
offsprings immune reactions. A study in a mouse model
(H. Renz, 1999).
study group
control group
Ovalbumin challenge(every second day)
decreased INF-g
( x 8 9 )
PREGNANCY BIRTH
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Direct evidence for transplacental allergen
transfer.Szpfalusi et al. Pediatr Res 2000, 48, 404-7.
maternal side fetal side
BLG 8 8
Bet v1 10 2
Human IgG = increase
= Ig receptor involvement
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Diagnosis of food allergy
1. IgE-mediated food allergy
- SPT IgE
2. Non-IgE-mediated food allergy
- patch test
- in vitro: LTT (cytokine profile?)
GOLDEN STANDARD = DBPCFC
research
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Future immunomodulatory
therapies for food allergy
1. Humanized monoclonal anti-IgE2. Mutated allergen protein immunotherapy
3. Peptide immunotherapy
4. Immuno-stimulatory sequences5. Probiotics (?) no effect on allergic reactions
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Alternative feedings in case of CMA
1. Breast milk
2. Soy formulas (?)
3. Goat formulas (?)
4. Hypoallergenic formulas
( partial hydrolysate formulas)
5. Amino acid-based formulas
(complete hydrolysate formulas
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(), Hypoallergenic milk group; (---) cows milk-based infant formula.
p = 0.093
Use of hypoallergenic formula in the prevention of
atopic disease among Asian children.
Chan et al. J Paediatr Child Health 2002; 38; 84-8.
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Primary prevention of atopy: food
allergen avoidance
-- BREAST FEEDING
Saarinen AM, Kajosaari M. Breastfeeding as prophylaxis
against atopic disease: prospective follow-up study until 17
years old. Lancet 1995; 346: 1065 - 1069.
-- HYPO-ALLERGENIC MILK
Vandenplas Y et al. The long-term effect of a partial wheyhydrolysate formula on the prophylaxis of atopic disease.
Eur J Pediatr 1995; 154: 488 - 494.
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The long-term effect of a partial whey hydrolysate
formula on the prophylaxis of atopic disease.Vandenplas et al. Eur J Ped 1995, 154, 488.
prevalence of CMP sensitivity
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Conclusion: Food Allergy
Fact or Fiction?
a lot of non-scientific data
opinions truths tradition
stories etc
scientific data
A fact surrounded with lots of fiction
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Conclusion
Still breast is best
but impossible to study
no contra-indications