1. Food allergy in children
Hugo Van Bever
Department of Pediatrics
National University Singapore
APAPARI Workshop, Hanoi, May 2008

2. 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”

3. Food allergy = an immunologically-mediated reaction against food
1. IgE-mediated
2. Cell-mediated reactions
(T lymphocytes - delayed onset)
3. Mixed types (atopic dermatitis)
4. Other mechanisms
( unknown - CIC – complement – etc…)

4. 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 %

5. 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 shock
5. OTHER: migraine, hyperactivity,
sleep disturbances etc… ?

6. 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. Bird’s nest 27 % 4.5
3. Chinese herbs 7 % 5.0
4. Crustacean seafood 24 %
5. Others * 30 % 7.0
* Chicken, duck, ham, fruits (banana, rambutan), cereals, gelatin and spices
Goh et al. Allergy 54, 1999,

7. Every food has its own story…
cow’s milk
hen’s egg
peanuts, fish, seafood, …
prevalence
age
6 months
3 yrs yrs

8. Sensitization to food… sensitization to allergens…
1. prenatal sensitization
2. postnatal sensitization

9. Sensitization to food… eating, touching and smelling…
peanuts
fish
hen's egg

10. Allergy to cow’s milk proteins in mother’s milk or in hydrolyzed cow’s milk infant formulas assessed by intestinal permeability measurements.
mother’s milk
ovalbumin
peanut protein
cow’s milk protein

11. Prenatal sensitization to allergens…does 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

12. Exposure to peanuts in utero and in infancy and the development of sensitization to peanut allergens in young children.
Frank L, Marian A, Visser M, Weinberg E, Potter PC. Pediatr Allergy Immunol 1999, 10,
… mothers who consumed peanuts more than once a week during pregnancy were more likely to have a peanut-allergic child than mothers who consumed peanuts less than once a week (odds ratio=3.97, 98% confidence interval ).

13. study group control group PREGNANCY BIRTH
Allergic sensitization during pregnancy influences the offspring’s immune reactions. A study in a mouse model (H. Renz, 1999).
study group
Ovalbumin challenge
(every second day)
decreased INF-g
( x 8 – 9 )
control group
PREGNANCY BIRTH

14. Direct evidence for transplacental allergen transfer. Szépfalusi et al
Direct evidence for transplacental allergen transfer. Szépfalusi et al. Pediatr Res 2000, 48,
maternal side fetal side
BLG
Bet v
Human IgG = increase
= Ig receptor involvement

15. Diagnosis of food allergy
1. IgE-mediated food allergy
- SPT – IgE
2. Non-IgE-mediated food allergy
- patch test
- in vitro: LTT (cytokine profile?)
research …
GOLDEN STANDARD = DBPCFC

16. Diagnostic decision points of 95% - cow’s milk 15 kU/L - egg 7 kU/L
Utility of food-specific IgE concentrations in predicting symptomatic food allergy. Hugh A. Sampson. JACI 2001, 107, 891.
Diagnostic decision points of 95%
- cow’s milk kU/L
- egg kU/L
- peanut kU/L
- fish kU/L
n = 100, mean age = 3.8 yrs

17. Future immunomodulatory therapies for food allergy
1. Humanized monoclonal anti-IgE
2. Mutated allergen protein immunotherapy
3. Peptide immunotherapy
4. Immuno-stimulatory sequences
5. Probiotics (?) no effect on allergic reactions

18. 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

19. 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:
-- HYPO-ALLERGENIC MILK
Vandenplas Y et al. The long-term effect of a partial whey hydrolysate formula on the prophylaxis of atopic disease. Eur J Pediatr 1995; 154:

20. 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

21. Conclusion: Food Allergy… Fact or Fiction?
… A fact… surrounded with lot’s of fiction
… a lot of non-scientific data … opinions… truths… tradition… stories … etc …
scientific data

22. Conclusion… Still … breast is best …but… impossible to study
… no contra-indications…