Hanoi Food Allergy

download Hanoi Food Allergy

of 30

Transcript of Hanoi Food Allergy

  • 7/28/2019 Hanoi Food Allergy

    1/30

    Food allergy in children

    Hugo Van Bever

    Department of Pediatrics

    National University Singapore

    APAPARI Workshop, Hanoi, May 2008

  • 7/28/2019 Hanoi Food Allergy

    2/30

    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

  • 7/28/2019 Hanoi Food Allergy

    3/30

    Adverse reactions to food

    Food intolerance (most common)

    Food allergy (hypersensitivity)

    Food aversion (phobia)

  • 7/28/2019 Hanoi Food Allergy

    4/30

    FOOD INTOLERANCE

    - toxins

    - infections

    - pharmacological properties of food

    - host factors (lactase deficiency)

  • 7/28/2019 Hanoi Food Allergy

    5/30

    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)

  • 7/28/2019 Hanoi Food Allergy

    6/30

    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 %

  • 7/28/2019 Hanoi Food Allergy

    7/30

    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 ?

  • 7/28/2019 Hanoi Food Allergy

    8/30

    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.

  • 7/28/2019 Hanoi Food Allergy

    9/30

    Common culprits - Singapore children

    Infants: cows milk

    hen's egg

  • 7/28/2019 Hanoi Food Allergy

    10/30

    Common culprits - Singapore children

    Older children

    seafood (shellfish), birds nest,

    Chinese herbs, eggs

  • 7/28/2019 Hanoi Food Allergy

    11/30

    FISHSweden 39% of food-

    allergic children are

    allergic to cod

    Uncommon in Singapore

    - per capita consumption of 25.05kg

  • 7/28/2019 Hanoi Food Allergy

    12/30

    Every food has its own story

    cows milk

    hens egg

    peanuts, fish, seafood,

    prevalence

    age

    3 yrs 5 yrs6 months

  • 7/28/2019 Hanoi Food Allergy

    13/30

    Sensitization to food

    sensitization to allergens

    1. prenatal sensitization

    2. postnatal sensitization

  • 7/28/2019 Hanoi Food Allergy

    14/30

    Sensitization to food

    eating, touching and

    smelling

    peanuts

    fish

    hens egg

  • 7/28/2019 Hanoi Food Allergy

    15/30

    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

  • 7/28/2019 Hanoi Food Allergy

    16/30

    Case

    9 month old boy

    Totally breastfed

    1st introduction of CM formula

    One minute after the first bite

  • 7/28/2019 Hanoi Food Allergy

    17/30

  • 7/28/2019 Hanoi Food Allergy

    18/30

    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

  • 7/28/2019 Hanoi Food Allergy

    19/30

  • 7/28/2019 Hanoi Food Allergy

    20/30

    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

  • 7/28/2019 Hanoi Food Allergy

    21/30

    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

  • 7/28/2019 Hanoi Food Allergy

    22/30

    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

  • 7/28/2019 Hanoi Food Allergy

    23/30

  • 7/28/2019 Hanoi Food Allergy

    24/30

    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

  • 7/28/2019 Hanoi Food Allergy

    25/30

    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

  • 7/28/2019 Hanoi Food Allergy

    26/30

    (), 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.

  • 7/28/2019 Hanoi Food Allergy

    27/30

    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.

  • 7/28/2019 Hanoi Food Allergy

    28/30

    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

  • 7/28/2019 Hanoi Food Allergy

    29/30

    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

  • 7/28/2019 Hanoi Food Allergy

    30/30

    Conclusion

    Still breast is best

    but impossible to study

    no contra-indications