Transcript Food For Thought - Prevention First

Food For Thought
Jeff Lehman, MD
Illinois WIC Conference
April 24, 2014
Definitions
Food Allergy (FA)
• An adverse health effect arising from a specific
immune response that occurs reproducibly on
exposure to a given food.
Food Intolerance (FI)
• Non-immunologic mechanism that involves
the digestive system and is not always
reproducible since many affected patients can
tolerate small amounts of culprit food without
symptoms.
Food Allergens
• Specific components of food or ingredients
within food (typically proteins, but sometimes
also chemical haptens) that are recognized by
allergen-specific immune cells and elicit specific
immunologic reactions, resulting in
characteristic symptoms.
Adverse Food Reactions
Non-immunologic
(primarily food intolerance)
Metabolic
(eg, lactose
intolerance)
Pharmacologic
(eg, caffeine)
Toxic
(eg, scombroid
fish toxin)
Adapted from Boyce et al. J Allergy Clin Immunol 2010;126:S1-58.
Idiopathic
(eg, sulfites)
Adverse Food Reactions
Immunologic
IgE mediated
(eg, acute
urticaria,
oral allergy
syndrome)
Non-IgE
mediated
(eg, food
proteininduced
enteropathy,
celiac disease)
Mixed IgE &
non-IgE
(eg,
eosinophilic
gastroenteritis)
Cell Mediated
(eg, allergic
contact
dermatitis)
Adapted from Boyce et al. J Allergy Clin Immunol 2010;126:S1-58.
Prevalence
• True prevalence of FA difficult to establish
▫ 170 foods reported to cause allergy, but prevalence
studies focus on most common foods.
▫ Studies of FA incidence, prevalence and natural
history are difficult to compare because of
inconsistencies and deficiencies in study design
and variations in definition of FA.
Prevalence
Dx
criteria
Overall prevalence
Self reported
sxs: children
12%
Self reported
sxs: adults
13%
Self reported
sxs: all ages
peanut
milk
egg
fish
shellfish
0.6%
3%
1%
0.6%
1.2%
Sxs + SPT or
RAST: all
ages
3%
0.75%
0.6%
0.9%
0.2%
0.6%
Food
challenge: all
ages
3%
NE
0.9%
0.3%
0.3%
NE
Rona RJ et al. The prevalence of food allergy: a meta-analysis.
J Allergy Clin Immunol 2007. 120(3):638-46.
Prevalence
Dx
criteria
Fruits
Vegetable
Tree nuts
Wheat
soy
Self
reported
sxs
0.02-8.5%
0.01-13.7%
0-4.1%
0.2-1.3%
0-0.6%
SPT
0.02-4.2%
0.01-2.7%
0.04-4.5%
0.2-1.2%
0.030.2%
0.1-4.3%
0.1-0.3%
0.1-4.3%
0-0.5%
0-0.7%
1.22%
0.1%
NE
0.4%
NE
NE
NE
0.5%
0.4%
NE
Food
Challenge
Metaanalysis:
adult
studies
Metaanalysis:
children
studies
Zuidmeer L et al. The prevalence of plant food allergies: a systematic review.
J Allergy Clin Immunol 2008. 121(5):1210-8.
When should food allergy be
suspected?
• Anaphylaxis or combination of symptoms that
occur within minutes to hours of ingesting food
• Infants, young children and selected older
children diagnosed with certain disorders such
as: moderate to severe atopic dermatits/eczema,
Eosinophilic GI disorders, protein induced
enterocolitis
Clinical Presentation
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Rapid onset (minutes to 2 hours)
Urticaria/Angioedema
Rhinoconjunctivitis
GI anaphylaxis
Generalized anaphylaxis
Oral allergy syndrome (OAS)
Food dependent exercise induced anaphylaxis
Associated conditions
• Atopic dermatitis
• Asthma
Urticaria/Angioedema
• Most common cutaneous manifestation
▫ Acute (< 6 wks)=most common manifestation
(~20% acute urticaria due to foods)
▫ Chronic (> 6 wks)- food uncommon
Rhinoconjunctivitis
• Common component
• Conjunctival injection, lacrimation, periorbital
edema, pruritus
• Isolated symptoms rare
GI anaphylaxis
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•
•
•
Nausea
Vomiting
Abdominal pain
Abdominal cramping
• Diarrhea
Minutes to 2 hrs
2 to 6 hrs
Generalized anaphylaxis
• Food causative in 50% ER treated
• Most common:
▫ Peanuts, tree nuts, fish, and shellfish
Oral allergy syndrome (OAS)
(pollen-food allergy syndrome)
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•
•
•
50% pts with allergic rhinitis to pollen
Food protein cross reactive with pollen protein
Sxs more noticeable during pollen season
Confined to oropharynx (minutes)
• pruritus, irritation, and mild swelling of the lips,
tongue, palate, and throat
• fresh, uncooked fruits and vegetables
• Progression to systemic sxs=<10%;
anaphylaxis=1-2%
Atopic dermatitis (AD)
• ~40% infants with mod-severe AD have food
allergies
• Conversely, 27 % of children with food allergy
are reported to have eczema or skin allergy vs.
8% of children without food allergy
• Food-related exacerbations of AD involve both
IgE-mediated and non-IgE mediated
hypersensitivity
Atopic Dermatitis
• Relationship between AD and food
▫ Elimination of suspected food allergens frequently
improves symptoms of AD
▫ Repeated exposure to suspect foods commonly
exacerbates skin symptoms
▫ Eliminating foods to which an infant has
demonstrable allergy can partially prevent the
development of atopic dermatitis
Asthma
• Isolated asthma uncommon
▫ Exception: Occupational asthma
 Baker’s asthma (inhaled wheat proteins)
Disorders Not Proven to be
Related to Food Allergy
• Migraines
• Behavioral / Developmental disorders
• Arthritis
• Seizures
• Inflammatory bowel disease
Non IgE-mediated
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Lactose intolerance
Food protein-induced enterocolitis
Food protein-induced proctitis and proctocolitis
Celiac disease
Food-induced pulmonary hemosiderosis
(Heiner's syndrome)
Lactose intolerance
• Abdominal pain/cramping, bloating, flatulence,
diarrhea, and vomiting
• Intolerance to lactose-containing foods
(primarily dairy products) is common
▫ In Europe and the United States, the prevalence is
7 to 20% in Caucasian, 80 to 95% among Native
Americans, 65 to 75% among Africans and African
Americans, and 50% in Hispanics
Food protein-induced enterocolitis/proctitis
• Cell-mediated
• Infants <9 months (1wk-3months)
• Cow's milk or soy, although oat, rice, and
poultry are other causative foods
• Rare when solely breastfed
• Vomiting, diarrhea, malabsorption, or bloody
stools
• Resolution with restriction of causative food
Celiac disease
 aka gluten-sensitive enteropathy or nontropical
sprue
 triggering proteins are wheat, barley, and rye
 Sxs: diarrhea, anorexia, abdominal distension and
pain, and failure to thrive or weight loss
 Skin manifestations
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Dermatitis herpetiformis
Eczema
Epidermal necrolysis
Pityriasis rubra
Pustular dermatitis
Cutaneous vasculitis
Cutaneous amyloid
Celiac disease
• Diagnosis
▫ IgA (IgG) antibodies against tissue
transglutaminase (anti-tTG), which is highly
sensitive, specific, and most cost-effective
▫ IgA (IgG) antibodies to endomysium
▫ Small Intestinal Biopsy
• Treatment
▫ Gluten free diet for life resolution
Food-induced pulmonary hemosiderosis
(Heiner's syndrome)
• Recurrent pneumonia with pulmonary
infiltrates, hemosiderosis, iron deficiency
anemia, and failure to thrive
• Infants
• Cow's milk = most common causative food
▫ pork and egg also reported
• IgG to cow’s milk protein
• Removal of food resolution
Eosinophilic esophagitis (EoE)
 Any age
 Children may present with feeding
disorders
 Older children and adults present with
dysphagia, vomiting, and abdominal pain
(A history of food impaction is common)
 Failure to respond to antacids and
antireflux therapies is an important aspect
of the history
EoE continued
 In a retrospective review of 381 children with
EE:
 most commonly implicated foods = cow's milk,
egg, soy, corn, wheat, and beef
 Elimination of these foods or the use of
elemental diets results in clinical and histologic
improvement in most
 However, the pathophysiologic relationship
between this disorder and food and
aeroallergens remains unclear
Summary
 The DDx = non-immunologic and immunologic disorders
 IgE-mediated food allergy typically develops rapidly after food
ingestion, ie, usually within minutes
 Symptoms can affect multiple organ systems cutaneous reactions
(urticaria, angioedema), rhinoconjunctivitis, gastrointestinal
anaphylaxis, generalized anaphylaxis, the oral allergy syndrome, and
food-dependent, exercise-induced anaphylaxis
 Atopic dermatitis &asthma are atopic conditions in which food allergy
may play a role in some patients, but is not the sole pathogenic
process
 Non-IgE-mediated food reactions present as more subacute
and/or chronic symptoms, which are more commonly isolated to
the gastrointestinal tract
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food protein-induced enterocolitis
food protein-induced proctitis/proctocolitis
celiac disease
food-induced pulmonary hemosiderosis (Heiner's syndrome)
Eosinophilic esophagitis and gastroenteritis
Diagnostic Tools (IgE mediated)
• Clinical history is critical in the diagnosis
• Prick/puncture skin testing
Must always be
interpreted in the
• In vitro testing
context of clinical
history
• Food challenge
• Food elimination diets
History
• What are the symptoms?
• What food precipitates the symptoms?
▫ Has this food caused symptoms more than once?
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•
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Was the food baked or uncooked?
How long after exposure did symptoms occur?
Has the food been eaten without symptoms?
Have symptoms occurred without food exposure?
Skin testing (Skin prick)
• Advantages:
▫ Commonly used in the evaluation of a suspected IgEmediated food allergy
▫ Highly reproducible
▫ Inexpensive
▫ Results in 15 minutes
▫ Sensitivity/Specificity- 90%/%50
▫ >95 % Negative predictive value
• Disadvantages:
▫
▫
▫
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Low positive predictive value
Patient must be off antihistamines
Need to wait 2-4 weeks after anaphylaxis
Possibility of precipitating systemic reaction
What age can we test?
• Not formally studied
• The skin of infants may be less reactive, yielding
more false negative results
• Positive results are commonly obtained in infants
with a history consistent with food allergy
• Unfortunately, very young children may also have
more systemic reactions to skin testing
• Skin testing can be performed even in infants and
young children, when indicated and with
appropriate precautions
Atopy patch testing
• Topical application of a food-containing solution
to the skin for 48 hours
• Shown promise in the diagnosis of nonIgE mediated food allergy
• No standardized reagents, application methods,
or guidelines for interpretation
• Not recommended outside of research settings
In vitro testing
• Allergen-specific serum IgE (sIgE)
▫ Radioallergosorbent testing (RAST)
▫ Fluorescent enzyme immunoassay (FEIA)
• Advantages
▫ Unaffected by antihistamines
▫ Useful in patients with severe anaphylaxis
▫ Useful in patients with severe atopic dermatitis or
dermographism
• Disadvantages
▫ Less sensitive than SPT
 Sensitivity 89% & Specificity 91%
▫ More Expensive
▫ Must wait for results
Oral Food Challenge
• DBPCFC is gold standard
▫ Expensive and inconvenient
• Single-blind or open challenge
▫ Usually diagnostic
▫ Patients must:
 Be off antihistamines
 Avoided food in question for at least 2 weeks
Food elimination diets
• Elimination of 1 or a few specific foods may be
useful
• More useful in mixed IgE- and non-IgE
mediated food induced allergic disorders
• Prolonged elimination diets that omit multiple
foods have been reported to induce severe
malnutrition
Nonstandardized and unproven tests
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Basophil histamine release
Allergen specific IgG
Lymphocyte stimulation
Hair analysis
Applied kinesiology
Electrodermal test
Mediator release assay (LEAP diet)
Gastric juice analysis
Endoscopic allergen provocation
Management
Management of Food Allergy
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Complete avoidance of specific food trigger
Ensure nutritional needs are being met
Education
Anaphylaxis Emergency Action Plan if
applicable
▫ most accidental exposures occur away from
home
This frozen dessert could have
peanut, tree nut, cow’s milk,
egg, wheat
Management: Dietary Elimination
• Hidden ingredients in restaurants/homes (peanut
in sauces, egg rolls)
• Labeling issues (“spices”, changes, errors)
• Cross contamination (shared equipment)
• Seeking assistance
▫ Food allergy specialist
▫ Registered dietitian: (www.eatright.org)
▫ Food Allergy & Anaphylaxis Network
(www.foodallergy.org; 800-929-4040) and local
support groups
Label reading used to be very challenging!
Example: Cow’s Milk
Contain cow’s milk: Artificial butter flavor, butter, butter fat, buttermilk,
casein, caseinates (sodium, calcium, etc.), cheese, cream, cottage cheese,
curds, custard, Half&Half®, hydrolysates (casein, milk, whey), lactalbumin,
lactose, milk (derivatives, protein, solids, malted, condensed, evaporated,
dry, whole, low-fat, non-fat, skim), nougat, pudding, rennet casein, sour
cream, sour cream solids, sour milk solids, whey (delactosed,
demineralized, protein concentrate), yogurt. MAY contain milk: brown
sugar flavoring, natural flavoring, chocolate, caramel flavoring, high protein
flour, margarine, Simplesse®.
AS of January 1, 2006, all food containing “Big Eight
Allergens” (cow’s milk, peanut, tree nut, hen’s egg, soy, wheat,
fish, crustacean) in the U.S. MUST declare the ingredient on
the label in COMMON language. Does NOT apply to non-Big 8
allergens (e.g., sesame).
Food Allergen Labeling and Consumer Protection Act of 2004 (P.L. 108-282)
(FALCPA)
Food labeling
• Education and training on how to interpret
ingredient lists on food labels and how to
recognize labeling of the allergens used as
ingredients.
• Food allergen labeling and consumer protection
act (FALCPA) 2004
▫ Require food labels to disclose the presence of any
of the 8 major food allergens when used as
ingredients (milk, egg, peanut, tree nuts, soy,
wheat, fish, and shellfish)
▫ Precautionary labeling is voluntary
Advisory Labeling
• Not an intended ingredient of the food, but
rather may contact or become a part of the food
despite accepted manufacturing processes
▫ "may contain"
▫ "processed in a facility with"
▫ "manufactured on shared equipment with”
• Advise patients to avoid these foods, because it
is impossible for the consumer to determine the
actual risk, and serious reactions from crosscontact have been reported .
Management: Infant Formulas
• Soy (confirm soy IgE negative)
▫ <15% soy allergy among IgE-CMA
▫ ~50% soy allergy among non-IgE CMA
• Cow’s milk protein extensive hydrolysates
▫ >90% tolerance in IgE-CMA
• Partial hydrolysates
▫ Not hypoallergenic!
• Elemental amino acid-based formulas
▫ Lack allergenicity
* CMA=cow’s milk allergy
Dietary avoidance in IgE-mediated FA
• Individuals with documented IgE-mediated food
allergy should avoid ingesting their specific
allergen or allergens.
• There is no evidence that strict food avoidance
compared with less strict avoidance has any
effect on the rate of natural remission.
Effects of dietary avoidance on
associated comorbid conditions
• Individuals with proven food allergy who also
have 1 or more of the following, atopic
dermatitis, asthma or eosinophilic GI disorders ,
should avoid their specific allergen.
• Food allergen avoidance may reduce the severity
of atopic dermatitis or eosinophilic GI disorders.
.
Food avoidance and nutritional status
• Nutritional counseling and regular growth
monitoring for all children with food allergy.
• No randomized clinical studies to show whether
food allergen avoidance diminishes nutritional
status.
• Studies in which growth measurements were
evaluated against diet records suggest that
children with food allergy are at risk for
inadequate nutritional intake.
Food avoidance and nutritional status
• Children with 2 or more food allergies were shorter
than those with one food allergy (p<0.05)
• Children with milk allergy or multiple food allergies
were more likely to consume dietary calcium at less
than gender specific recommendations
• The possibility of consuming a less than
recommended intake of calcium and vitamin D in
children with food allergy was less if the child
received nutrition counseling (p<0.05)
Maternal dietary avoidance of allergens
for infants with proven food allergy
• Food allergens ingested by the mother can be
detected in breast milk
• Allergic reactions, including anaphylaxis, can
occur in the infant
• Infants may have chronic atopic dermatitis or
gastrointestinal symptoms (vomiting, diarrhea,
failure to thrive, proctocolitis)
• When mothers follow avoidance diets,
nutritional issues should be addressed
Lifschitz CH et al. J Pediatr Gastroenterol Nutr. 1988 Jan;7(1):141-4.
Pharmacological intervention for
treating mild food-induced allergic
reactions
• Allergen avoidance is first line
• Antihistamines as needed for non-severe foodinduced allergic reactions.
• Close observation to monitor for progression to
anaphylaxis
• Food-allergy action plan
• Epi autoinjector for patients with history of
severe reaction or with known food allergy to
peanut, tree nut, fish or shellfish.
Quality of life issues associated with
food allergy
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Anxiety
Overprotective parents
Family social activities
Home schooling
Dietary avoidance of cross reactive
foods in at risk patient’s
• Patients at risk for developing food allergy do
not need to limit exposure to foods that may be
cross-reactive with the 8 major food allergens.
• There is insufficient evidence to determine
whether eating foods that cross react with the
major allergenic foods will cause symptoms.
• Unnecessary food avoidance can result in
inadequate nutrient intake and growth deficits.
Testing of allergenic foods in patients
at high risk prior to introduction
• Insufficient evidence to recommend routine food
allergy testing prior to introduction of highly
allergenic foods such as milk, egg and peanut.
• There may be some value of doing an oral food
challenge for a select group of patients with certain
risk factors such as a sibling with peanut allergy.
• Skin prick testing and specific IgE tests are not
recommended because of their poor predictive
value.
▫ May lead to unnecessary diet restrictions if
unconfirmed by oral food challenges.
Prevention of food allergy
• Maternal diet during pregnancy and lactation
▫ Not recommended to restrict diet as a strategy for
preventing development of FA
• Breast-feeding
▫ Exclusive for 4-6 months
• Special diets in infants
▫ Recommends against using soy infant formula
instead of cow’s milk formula to prevent FA in at
risk infants
Prevention of food allergy
• Hydrolyzed vs cow’s milk infant formulas
▫ Use of hydrolyzed formulas as opposed to cow’s
milk formulas may be considered a strategy for
preventing FA in at risk infants who are not
exclusively breast-fed
• Timing of introduction of allergenic foods to
infants
▫ Introduction of solid foods should not be delayed
beyond 4-6 months including potentially
allergenic foods
Natural History
• Cow’s milk protein
▫ Non–IgE-mediated usually transient, which is almost
always outgrown
▫ IgE-mediated may persist through adolescence and
beyond
• Hen’s egg
▫ Most reactions are IgE-mediated
▫ Majority resolve within childhood or adolescence
• Wheat
▫ resolves in 80 percent of patients by five years of age
▫ majority of cases resolve by adolescence
Natural History
• Peanut
▫ 20-25% lose sensitivity
▫ Up to 4% can have recurrence
• Tree Nut
▫ ~10% lose sensitivity
When to re-evaluate
• Depends on the food in question, age of the child
and intervening medical history
• In children, a drop in sIgE levels or reduction in SPT
wheal over time is often a marker for onset of
tolerance
• Children will likely outgrow allergies to milk, egg,
soy and wheat
• Less likely to outgrow allergies to peanut, tree nuts,
fish and shellfish
▫ Peanut: ~20-25% resolve
▫ Tree nut: ~10% resolve
Reasons for Allergy Referral
• Persons who have limited their diet based upon
perceived adverse reactions to foods or additives.
• Persons with a diagnosed food allergy
• Atopic families with, or expecting, a newborn who
are interested in identifying risks for, and
preventing, allergy.
• Persons who have experienced allergic symptoms
in association with food exposure.
• Persons who experience an itchy mouth from raw
fruits and vegetables.
Leung D, et al. J Allergy Clin Immunol
2006;117:S495-523.
Reasons for Allergy Referral
(Cont’d)
• Infants with recalcitrant gastroesophageal reflux or older
individuals with recalcitrant reflux symptoms, particularly
if they experience dysphagia.
• Infants with gastrointestinal symptoms including vomiting,
diarrhea (particularly with blood), poor growth, and/or
malabsorption whose symptoms are otherwise
unexplained, not responsive to medical management,
and/or possibly food-responsive (even if screening allergy
tests are negative).
• Persons with known eosinophilic inflammation of the gut.
Leung D, et al. J Allergy Clin Immunol
Role of the Allergist
• Identification of causative food
• Institution of elimination diet
• Education on food avoidance
• Development of an Anaphylaxis Emergency
Action Plan
• Prevention of other allergies
• Follow-up to ascertain tolerance
References
• Boyce, JA et al. Guidelines for the Diagnosis and
Management of Food Allergy in the United
States: Report of the NIAID-Sponsored Expert
Panel. J Allergy Clin Immunol 2010. 126(6):S158.