Allergies are increasing worldwide, especially in developed countries. Food allergies are becoming most common in infants and children. There are some things that can be done to potentially reduce allergy risk in high-risk infants. Exclusive breastfeeding for at least 4 months and introducing complementary foods between 4-6 months may help reduce risks. For high-risk infants who are formula-fed, a hydrolyzed formula is recommended. Introduction of highly allergenic foods should be done gradually under medical supervision for high-risk infants. While prevention efforts show some promise, more research is still needed.

2. ‫اآلية‬ ‫البقرة‬ ‫سورة‬32

3. Can we prevent
allergies in children?
What are they and can we
prevent them?
Khaled Saad, MD

4. Introduction
◼ Allergic disorders continue to increase
throughout the world •Asthma-8.2% of US
population; 9.4% of children. Up to 30% in some
populations, particularly developed countries.
◼ Food allergies are becoming most
common in infants and children.
◼ Most present management treats
symptoms; none of our treatments cure
these conditions.

5. Are there things we
can do to reduce the
risk of allergies
developing in our
“high risk”
population?

6. What is the incidence of food
allergy in young children?
a) <10%
b) 10-20%
c) 20-30%
d) >30%
Garcia-Careaga, 2005

7. Immunology to food
allergy
Definitions

8. Immune system
The immune system is a host’s
defense system comprising of
many biological structures and
processes within an organism that
protects him from a disease.
It is the body's defense
management against infectious
organisms and other invaders.

9. Antigen
◼An antigen is a protein on a
foreign object that stimulates the
immune system to produce
antibodies (Ab).
◼An antigen may be a virus,
bacteria, toxin, pollen, etc that
triggers the immune response in
the body.

10. Antibody
Antibody, also called immunoglobulin,
a protective protein produced by the
immune system in response to the
presence of a foreign substance, called
an antigen.
Antibodies recognize and handle onto
antigens in order to remove them from
the body.

11. Allergy – “a pathological immune
reaction to a food protein”
Adverse food reaction – “an ill effect as
a result of the intake of food”
•Intolerances, sensitivities, enzyme
deficiency (e.g. galactosemia,
disaccharidase, etc),
pharmacological effect (e.g. food
dyes, preservatives, caffeine, etc)

12. Antigen-Antibody response
◼ When an unknown substance enters the
body, the immune system is able to
recognize it as foreign because molecules
on the surface of the antigen differ from
those found in the body.
◼ To eliminate the invader, the immune
system calls on a number of mechanisms,
including one of the most important-
Antibody production.

13. ◼ Antibodies attack antigens by binding to
them. Antigens & antibodies combine
specifically with each other. This
interaction between them is called
‘Antigen-Antibody reaction’.
◼ The binding of an antibody to an antigen
can neutralize its action by simply
changing its chemical composition.
◼ Once begun, antibody production
continues for several days until all
antigen molecules are removed.

14. What is an Allergy?
◼ Allergies are caused by an abnormal
response of the immune system. The
immune system reacts to a usually
harmless substance in the
environment. This substance can be
pollen, mold, dust, animal dander,
certain foods, insect stings, etc. and
is referred to as an allergen.

16. Food allergy
◼ Food allergy is an immune system reaction
that occurs soon after eating a certain food.
◼ It occurs when the body’s immune system
sees a certain food as harmful and reacts by
causing symptoms such as digestive
problems, hives or swollen airways. This is
an allergic reaction.
◼ Foods that cause allergic reactions are
allergens.

17. Eight foods that are
responsible for the
majority
of allergic reactions:
1. Milk (mostly in
children)
2. Eggs 3. Peanuts
4. Tree nuts, like walnuts,
almonds, pine nuts,
brazil nuts, and pecans
5. Soy 6. Wheat and other
grains with gluten,
including barley, rye, and
oats 7. Fish (mostly in
adults) 8. Shellfish (mostly
in adults)

18. Type 1: IgE-mediated
(immune)
◼ Immediate Hypersensitivity Disorder
– Symptoms occur in minutes to hours
– Can become anaphylactic
– Common triggers are milk, soy, egg, peanut,
shellfish, wheat
– 80% resolve after several years with the
exception of peanut and shellfish
Garcia-Careaga et al, 2005

20. Type 1: IgE-mediated
◼ Oral Allergy Syndrome/Pollen-Food
Allergy Syndrome
– Symptoms occur in minutes to hours
– Reaction limited to oral cavity
– Rarely systemic symptoms
– Common triggers are RAW fruit and
vegetables
– Cross-reaction with airborne allergens

21. Type III and IV:
Non-IgE Immune Mediated
◼ Proctocolitis (Cow’s Milk Protein Colitis)
– Occurs in infancy resolves between 6
months-2 years
◼ Dietary Food Enteropathy
– Occurs in infancy, usually resolves in first 2
years of life

22. Mixed IgE and Non-IgE
◼ Eosinophilic Gastroenteritis
– Eosinophilic infiltration of esophagus,
stomach and small bowel mucosa
◼ Eosinophilic Esophagitis
◼ Both conditions diagnosed by biopsy

23. Other Adverse Food Reactions
◼ Lactose Intolerance
– Reaction to milk sugar NOT protein
◼ Dietary Fructose Intolerance
– Reaction to the sugar fructose
◼ Food Sensitivities e.g. gluten

24. Conventional Diagnostic Tools
IgE-Mediated
◼ Skin prick testing
◼ RAST
radioallergosorbent
test – blood test
◼ Double-blind
placebo control
challenge
Non-IgE
◼ Stool samples for
blood, pus cells
◼ Endoscopy with
biopsy
◼ Elimination diets

25. Is Prevention Possible? Who do
we target to reduce the risk of the
atopic march?
◼ No evidence for prevention in general
population.
◼ Some evidence in high risk infants. High
risk = first degree relative with atopy
(eczema, food allergy, asthma, allergic
rhinitis).

26. 50% to 80% of children will have
some form of allergy if both
parents have an atopic history
Percentage of children that developed an
allergic manifestation
Potential for
Childhood
Allergy
Correlates
To Parents’
History of
Allergy

27. Risk Reduction. What’s
the Data?
Maternal Dietary Avoidance
Intervention

28. I. Maternal Dietary Avoidance
Intervention
Faith-Magnusson, K. JACI 1992
◼ The 209 mothers to be, enrolled in a randomized,
prospective, allergy-prevention study from allergy-
prone families, totally abstained from cow's milk and
egg from gestational week 28 to delivery.
◼ Looked at the development of allergic disease at 5
years of age in their children, compared with the
development of allergic disease in the children of the
control mothers
◼ There was NO significant difference in eczema,
allergic rhinoconjunctivitis, and asthma

29. ◼ Maternal avoidance during pregnancy or
lactation of essential foods such as milk
and egg is not recommended at this time.
◼ Regarding peanut ingestion and peanut
allergy in children, data are inconclusive
to make recommendations for peanut
avoidance during pregnancy at this time.
◼ Note: For mothers that choose to avoid
foods during pregnancy or lactation,
dietary counseling with a nutritionist is
recommended.

30. II. Breastfeeding for primary
prevention
◼ Recommendation:
Exclusive breastfeeding is
recommended for at least 4
months and up to 6 months of
age.

31. ◼ To possibly reduce the incidence of atopic
dermatitis in children younger than 2
years.
◼ To reduce the early onset of wheezing
before 4 years of age, but not necessarily
to reduce asthma.
◼ To reduce the incidence of cow’s milk
protein allergy in the first 2 years of life,
but not necessarily to reduce food allergy
in general.

32. ◼ There are no clear effects of breastfeeding
on allergic rhinitis.
◼ Data are conflicting about whether
exclusive breastfeeding longer than 3
months has an effect on the incidence of
atopic dermatitis in children.
◼ Despite some studies that showed an
increased risk of allergic disease with
exclusive breastfeeding, the overall benefits
of breastfeeding on the general health of
the child are likely to outweigh the
potential drawbacks.

33. III. Selection of infant formula
for primary prevention
◼ Recommendation:
For infants at increased risk of allergic
disease who cannot be exclusively
breastfed for the first 4 to 6 months, a
hydrolyzed formula may offer
advantages to prevent atopic dermatitis.

35. ◼ Partially hydrolyzed and extensively
hydrolyzed formulas may have a
preventive effect on atopic dermatitis when
used in the first 6 months of life instead of
intact cow’s milk protein formula.
◼ No evidence to support soy formulas or
amino acid formulas for prevention of
allergic disease.
◼ No evidence to support the use of a
formula over breastfeeding to prevent
atopic disease.

36. IV. Introduction of complementary
foods for primary prevention
◼ Recommendation (1):
Complementary foods can be
introduced between 4 and 6 months of
age, when an infant is developmentally
able to sit with support and has
sufficient neck control.

37. ◼ Most pediatric guidelines suggest first
introducing single ingredient foods
between 4 to 6 months of age, with one
new food every 3 to 5 days.
◼ There is no need to delay acidic fruits
(berries, tomatoes, citrus fruits) and
vegetables that may cause a perioral rash
or irritation since they do not usually
result in systemic reactions.

38. ◼ Whole cow’s milk as the infant’s main
drink should be avoided until 1 year of
age due to the increased renal solute load
and low iron content. Cow’s milk protein
in the form of infant formula, yogurt and
cheese can be introduced before age 1
year.
◼ Whole nuts should be avoided due to
potential aspiration risk. Peanuts and
tree nuts in the form of peanut/ tree nut
butters or other formulations can be
introduced.

39. Recommendation (2): Counsel parents how
to introduce highly allergenic foods in the
following manner:
◼ Introduce highly allergenic foods after other
complementary foods have been introduced and
tolerated.
◼ Introduce an initial taste of a highly allergenic food at
home, rather than at a day care or restaurant. Note:
Advise parents that for some foods, such as peanuts,
most reactions occur in response to the initial
ingestion.
◼ Gradually increase the amount of the highly
allergenic food if there is no reaction.
◼ Introduce other new foods at a rate of one new food
every 3 to 5 days if no reaction occurs.

40. Recommendation (3):
Consult with an allergist/
immunologist for the development
of a personalized plan for
complementary food introduction
for any of the following scenarios:

41. ◼ An infant has moderate to severe atopic dermatitis despite
optimal management.
◼ An infant has had an immediate allergic reaction to a food
or has a known food allergy, which puts them at higher
risk for other food allergies.
◼ An infant has a sibling with a peanut allergy. Although
peanut could be introduced with low risk at home, parents
or physicians may request allergy consultation with
testing prior to peanut introduction.
◼ Either an infant with positive serologic food-specific
serum IgE testing to a food not yet introduced or an
infant with undetectable food-specific IgE serum testing
despite convincing history of an allergic reaction.
◼ Note: Routine serologic food-specific IgE screening on
children without a history of an allergic reaction or other
symptoms/signs of food-related allergic disease is not
recommended.

42. History

43. Prevention Guidelines – AAP
Only for High Risk Infants
2000
◼ Pregnancy possibly restrict peanut
◼ Exclusive breastfeeding for 6 months
◼ Eliminate peanuts & nuts from lactation diet
(consider eggs, cow’s milk, fish)
◼ If bottle-fed use hypoallergenic formula
(extensive of partial hydrolysate)
◼ Solids at 6 mo; cow’s milk at 12 mo; eggs at
24 mo; peanuts, nuts and fish at 36 mo

44. Prevention Guidelines 2004
Euro Academy of Allerg and Clin Immunol
◼ Breastfeed exclusively for 4 months
◼ If bottle-fed use extensively hydrolyzed
formula
◼ Solids at 4 to 6 months
◼ Additional studies required to
demonstrate any preventive effects of
further dietary restriction

45. Prevention Guidelines – AAP
Only for High Risk Infants
2008
◼ No dietary restrictions during pregnancy or
lactation
◼ Exclusive breastfeeding for 6 months
◼ If bottle-fed use extensively hydrolyzed
formulas
◼ Solids at 4 to 6 months, no evidence to
support delayed introduction of foods
considered to be allergenic

47. Take Home Messages
◼ Encourage exclusive breastfeeding for 6
months (WHO guidelines)
◼ If bottle-feeding use extensively
hydrolyzed formula if high risk infant
◼ Avoid introduction of solid foods until 4-
6 months of age
◼ Stay tuned, this isn’t the end of the
story!

48. References
Garcia-Careaga et al. Gastrointestinal Manifestations of Food
Allergies in Pediatric Patients. Nutr in Clin Prac 20:526-535,
2005.
Herman, P & Drost, L. Evaluating the Clinical Relevance of Food
Sensitivity Tests: A Single-Subject Experiment. Alt Med Review
9(2):198-207.
Joneja, J. Food Allergy in Adults. Dietitians of Canada Current
Issues, 2007.
Joshi et al. Interpretation of Commercial Food Ingredient Labels by
Parents of Food-Allergic Children. Ann Allergy Asthma Immunol
90:84-89, 2003.
Muraro et al. Dietary Prevention of Allergic Diseases in Infants and
Small Children. Pediatr Allergy Immunol 15:291-307, 2004.
Pyrhonen et al. Occurrence of parent-reported food
hypersensitivities and food allergies among children aged 1-4 yr.
Pediatr Allergy Immunol 20:328-338, 2009.
Wennergren, G. What if it is the other way around? Early
introduction of peanut and fish seems to be better than
avoidance. Acta Paediatrica 98:1085-1087, 2009.