Download Diagnosis of Food Allergy and Intolerance

SUCCESS WITH FOOD
ALLERGY AND
INTOLERANCE
Janice Joneja Ph.D., RD
Food Allergy & Food Intolerance
DEFINITIONS:
Food Allergy
Food Intolerance
A generic term
An immunologic
describing an abnormal
reaction resulting
physiological response
from the ingestion
to an ingested food or
of a food or
food additive which is
food additive
not immunogenic
2
Symptoms of Food Allergy

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Controversy among practitioners because there are
no definitive tests for food allergy
Symptoms appear in diverse organ systems:
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Skin and mucous membranes
Digestive tract
Respiratory tract
Systemic (anaphylaxis)
Symptoms in nervous system are considered more
subjective and sometimes may be dismissed as
fictitious or psychosomatic
3
Examples of Allergic Conditions
and Symptoms

Skin and Mucous Membranes
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Atopic dermatitis (eczema)
Urticaria (hives)
Angioedema (swelling of tissues, especially mouth and
face)
Pruritus (itching)
Contact dermatitis (rash in contact with allergen)
Oral symptoms (irritation and swelling of tissues
around and inside the mouth)
Oral allergy syndrome
4
Examples of Allergic Conditions
and Symptoms

Digestive Tract
Diarrhea
 Constipation
 Nausea and Vomiting
 Abdominal bloating and distension
 Abdominal pain
 Indigestion (heartburn)
 Belching

5
Examples of Allergic Conditions
and Symptoms

Respiratory Tract
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Seasonal or perennial rhinitis (hayfever)
Rhinorrhea (runny nose)
Allergic conjunctivitis (itchy, watery, reddened eyes)
Serous otitis media (earache with effusion) [“gum ear”;
“glue ear”]
Asthma
Laryngeal oedema (throat tightening due to swelling of
tissues)
6
Examples of Allergic Conditions
and Symptoms

Nervous System
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Migraine
Other headaches
Spots before the eyes
Listlessness
Hyperactivity
Lack of concentration
Tension-fatigue syndrome
Irritability
Chilliness
Dizziness
7
Examples of Allergic Conditions
and Symptoms

Other
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Urinary frequency
Bed-wetting
Hoarseness
Muscle aches
Low-grade fever
Excessive sweating
Pallor
Dark circles around the eyes
8
Anaphylaxis


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Severe reaction of rapid onset, involving
most organ systems, which results in
circulatory collapse and drop in blood
pressure
In the most extreme cases the reaction
progresses to anaphylactic shock with
cardiovascular collapse
This can be fatal
9
Anaphylaxis

Usual progress of reaction
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Burning, itching and irritation of mouth and oral tissues
and throat
Nausea, vomiting, abdominal pain, diarrhea
Feeling of malaise, anxiety, generalized itching,
faintness, body feels warm
Nasal irritation and sneezing, irritated eyes
Hives, swelling of facial tissues, reddening
Chest tightness, bronchospasm, hoarseness
Pulse is rapid, weak, irregular, difficult to detect
Loss of consciousness
Death may result from suffocation, cardiac arrhythmia,
or shock
10
Foods and Anaphylaxis
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Almost any food can cause anaphylactic reaction
Some foods more common than others:
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Peanut
Tree nuts
Shellfish
Fish
Egg
In children under three years
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Cow’s milk
Egg
Wheat
Chicken
11
Exercise-induced Anaphylaxis
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Usually occurs within two hours of eating the
allergenic food
Onset during physical activity
Foods most frequently reported to have induced
exercise-induced anaphylaxis:
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Wheat (omega-5-gliadin) and other grains
Celery and other vegetables
Shellfish (shrimp; oysters)
Chicken
Squid
Peaches and other fruits
Nuts especially hazelnut
Peanuts and soy beans
May be associated with aspirin ingestion
12
Emergency Treatment for
Anaphylactic Reaction
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Injectable adrenalin (epinephrine)
Fast-acting antihistamine (e.g. Benadryl)
Usually in form of TwinJect® or Epipen®
Transport to hospital immediately
Second phase of reaction is sometimes fatal,
especially in an asthmatic

Patient may appear to be recovering, but 2-4 hours
later symptoms increase in severity and reaction
progresses rapidly
13
Immunologically Mediated
Reactions
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IgE-mediated:
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Immediate onset (anaphylaxis)
Oral allergy syndrome (OAS)
Latex-Food syndrome
Non-IgE-mediated
Eosinophilic gastrointestinal diseases
Food protein-sensitive enteropathies
Gluten-sensitive enteropathy (celiac disease)
14
Role of the Dietitian

Accurate identification of the foods
responsible
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Elimination and challenge to confirm or refute:

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allergy tests
suspected allergens and intolerance triggers
Directives for avoidance of the culprit foods
Recognition of sources of the offenders
 Understanding new labelling laws

15
The Dietitian’s Role

Provide guidelines and resources to ensure complete
balanced nutrition from alternative foods
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Directives for prevention of food allergy and
induction of oral tolerance
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Macronutrients
Micronutrients
New guidelines
Ensure freedom from allergens in food provision and
preparation services
16
Tests for Adverse Reactions
to Foods
Rationale and Limitations
Skin Tests:
Value in Practice

Positive predictive accuracy of skin tests
rarely exceeds 50%
 Many practitioners rate them lower

Negative skin tests do not rule out the
possibility of non-IgE-mediated reactions
Do not rule out non-immune-mediated food
intolerances

18
Value of Skin Tests in Practice

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Tests for highly allergenic foods thought to
have close to 100% negative predictive
accuracy for diagnosis of IgE-mediated
reactions
Such foods include:
 Egg
 Milk
 Fish
 Wheat
 Tree nuts
 Peanut
19
Blood Tests
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RAST: radioallergosorbent test (e.g. ImmunoCap-RAST;
Phadebas-RAST)
FAST; Fluorescence allergosorbent test
ELISA: enzyme-linked immunosorbent assay
Designed to detect and measure levels of allergen-specific
antibodies
Used for detection of levels of allergen-specific IgE
May measure total IgE - thought to be indicative of “atopic
potential”
Some practitioners measure IgG
(especially IgG4) by ELISA
20
Value of Blood Tests in Practice
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Blood tests have about the same sensitivity as skin
tests for identification of IgE-mediated sensitisation
to food allergens
There is often poor correlation between high level of
anti-food IgE and symptoms when the food is eaten
Many people with clinical signs of food allergy show
no elevation in IgE
Reasons for failure of blood tests to indicate foods
responsible for symptoms are the same as those for
skin tests
21
Value of Blood Tests in Practice
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Anti-food antibodies (especially IgG) are
frequently detectable in all humans, usually
without any evidence of adverse effect
IgG production is likely to be the first stage
of development of oral tolerance to a food
Studies suggest that IgG4 indicates
protection or recovery from IgE-mediated
food allergy
22
Tests for Intolerance of Food Additives

There are no reliable skin or blood tests to detect food
additive intolerance
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Skin prick tests for sulphites are sometimes positive

A negative skin test does not rule out sulphite
sensitivity
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History and oral challenge provocation of symptoms
are the only methods for the diagnosis of additive
sensitivity at present

Caution: Challenge may occasionally induce
anaphylaxis in sulphite-sensitive asthmatics
23
Commercial Testing and Food Allergy
Management Programs
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LEAP (Lifestyle Eating and Performance);
Signet Diagnostic Corporation
Claims to “successfully treat … IBS, migraines,
fibromyalgia, autism, ADD/ADHD, IBD, urticaria,
chronic fatigue syndrome, obesity, etc.”
 Negative aspects:
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Testing based on “mediator release”
 Not a recognized accurate method for allergy testing
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Positive aspects
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Management includes elimination and challenge, food
substitutions and meal planning
24
Commercial Testing and Food Allergy
Management Programs
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Gemoscan Corporation:
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HEMOCODE™ (Gemoscan) Food Intolerance System,
and MenuWise™ Food Intolerance Plan “personalized
naturopathic nutritional programs that promote wellbeing.”
Available in retail stores (Rexall and Loblaws)
Price is $450 for 250 foods
Tests identify IgG antibody to foods
Customers receive support from pharmacist/naturopath,
including consultation on appropriate vitamins and
supplements
Negative aspects

There is no provision for dietetic counselling and thus a high
risk for nutritional deficiency when the “reactive foods” are
eliminated without sufficient knowledge to provide nutrients
from alternate sources
25
Unorthodox Tests
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Many people turn to unorthodox tests when
avoidance of foods positive by conventional test
methods have been unsuccessful in managing their
symptoms
Tests include:
 Vega test (electro-dermal)
 Biokinesiology (muscle strength)
 Analysis of hair, urine, saliva
 Radionics
 ALCAT (lymphocyte cytotoxicity)
26
Drawbacks of Unreliable Tests
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Diagnostic inaccuracy
Therapeutic failure
False diagnosis of allergy
Creation of fictitious disease entities
Failure to recognize and treat genuine disease
Inappropriate and unbalanced diets
Risk of nutritional deficiencies and dietrelated disease
27
Non-IgE-Mediated
Allergies
Eosinophilic Gastrointestinal Diseases
Food Protein Induced Enteropathies
Eosinophilic Gastrointestinal
Diseases (EGID)
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Expanded definition of food allergy now
encompasses any immunological response to food
components that results in symptoms when the food
is consumed
Example is group of conditions in the digestive tract
in which infiltration of eosinophils is diagnostic
Collectively these diseases are becoming known as
eosinophilic gastrointestinal diseases (EGID).
29
Characteristics of EGID
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Inflammatory mediators are released from
the eosinophils, and act on local tissues in
the esophagus and gastrointestinal tract,
causing inflammation
In eosinophilic digestive diseases there is no
evidence of IgE, therefore tests for IgEmediated allergy are usually negative
Unless there is a concomitant IgE-mediated
reaction to food
30
Eosinophilic Esophagitis
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Symptoms most frequently associated with EO
and considered to be typical of the disease include:
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Vomiting
Regurgitation of food
Difficulty in swallowing: foods are said to be sticking
on the way down
Choking on food
Heartburn and chest pain
Water brash (regurgitation of a watery fluid not
containing food material)
Poor eating
Failure to thrive (poor or no weight gain, or weight
loss)
31
Eosinophilic Esophagitis
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Although the symptoms resemble gastroesophageal reflux disease (GERD), the
reflux of EO dose not respond to the
medications used to suppress the gastric
acid and control regurgitation (antireflux
therapy) in GERD
There is emerging data to suggest that use
of acid-suppressing medications may
predispose patients to the development of
EoE
32
Diagnosis of EoE
Three criteria must be met:
 Clinical symptoms of esophageal
dysfunction
 Oesophageal biopsy with an eosinophil
count of at least 15 eosinophils per highpower (x400 mag) microscopy field
 Exclusion of other possible causes of the
condition
Dellon ES 2013
33
Eosinophilic Esophagitis
Foods most frequently implicated
in Children
Egg
 Cow’s milk
 Soy
 Wheat
 Corn
 Peanuts
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Tree nuts
 Shellfish
 Fish
 Beef
 Rye
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34
Six-Food Elimination Diet and EoE
Adult study 2013
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Foods eliminated:
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Cereals
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Wheat
Rice
Corn
Milk and milk products
Eggs
Fish and seafood
Legumes including peanuts
Soy
Lucendo et al 2013
35
Six-Food Elimination Diet and
EoE
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Indicators of positive outcome:
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Reduced eosinophil count: 73.1% of subjects
Maintained remission for 3 years
Incidence of single triggering factors:
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Biopsy eosinophil count (< 15/hpf)
Negative gastro-oesophageal reflux
Cow’s milk 61.9%
Wheat 28.6%
Eggs 26.2%
Legumes 23.8%
No correlation with allergy tests
36
Eosinophilic Gastroenteritis:
Diagnosis by biopsy:
Abnormal number of eosinophils in the
stomach and small intestine
Foods most frequently implicated
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Egg
Cow’s milk
Soy
Wheat
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Peanuts
Tree nuts
Shellfish
Fish
37
Eosinophilic Proctocolitis
Diagnosis by biopsy:
Abnormal number of Eosinophils confined to the
colon
Foods most frequently implicated
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Cow’s milk
Soy proteins
Most frequently develops within the first 60 days of life
Is a non-IgE-mediated condition
38
Food Protein Enteropathies
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Increasing recognition of a group of non-IgEmediated food-related gastrointestinal problems
associated with delayed or chronic reactions
Conditions include:
 Food protein induced enterocolitis syndrome
(FPIES)
 Food protein induced proctocolitis (FPIP)
These digestive disorders tend to:
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Appear in the first months of life
Be generally self-limiting
Typically resolve at about two years of age
39
FPIES Symptoms
Symptoms in infants typically include:
 Profuse vomiting
 Diarrhoea, which can progress to dehydration and
shock in severe cases
 Increased intestinal permeability
 Malabsorption
 Dysmotility
 Abdominal pain
 Failure to thrive (typically weight gain less than
10 g/day)
 In severe episodes the child may be hypothermic
(<36 degrees C)
40
FPIES Characteristics
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Triggered by foods, but not mediated by IgE
Condition typically develops in response to food
proteins as a result of digestive tract and
immunological immaturity
Cow’s milk and soy proteins, usually given in
infant formulae, reported as most frequent causes
Milk and soy-associated FPIES usually starts
within the first year of life; most frequently within
the first six or seven months
When solids foods are introduced, other foods
may cause the condition
Recent research claims that rice is the most
common food causing FPIES
41
Foods Associated with FPIES
Removal of the culprit foods usually leads to
immediate recovery from the symptoms
Foods that have been identified as triggers of FPIES
in individual cases include:
 Milk
 Cereals (oats, barley and rice)
 Legumes (peas, peanuts, soy, lentils)
 Vegetables (sweet potato, squash)
 Poultry (chicken, turkey)
 Egg
42
Prevention of FPIES
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Most reports of FPIES indicate that exclusive
breast-feeding is protective in potential cases of
FPIES
None of the infants who later developed FPIES
after the introduction of solids had symptoms
while being exclusively breast-fed
Authors of these studies suggest that babies with
FPIES while being breast-fed were sensitized to
the proteins through an infant formula given
during a period of immunological susceptibility
43
Diagnosis and Management of FPIES
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There are no diagnostic tests for FPIES at
present
Indicators include clinical presentation :
 development of acute symptoms
immediately after consumption of the
offending foods (often milk- or soy-based
infant formula)
 absence of positive tests for food allergy
Elimination and challenge with the suspect
foods will usually confirm the syndrome
44
Diagnosis and Management of FPIES
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Removal of the offending food leads to
symptom resolution
In most cases delayed introduction of solid
foods is advised because of the possibility that
until the child’s immune system has matured, a
similar reaction to proteins in other foods may
elicit the same response
45
Food Protein Induced
Proctitis/Proctocolitis
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Blood in the stool is typical
Condition typically appears in the first few months
of life, on average at the age of two months
The absence of other symptoms, such as vomiting,
diarrhoea, and lack of weight gain (failure to
thrive) usually rules out other causes such as food
allergy, and food protein enteropathies
Usually the blood loss is very slight, and anaemia
as a consequence of loss of blood is rare
Diagnosis is usually made after other conditions
that could account for the blood, such as anal
fissure and infection, have been ruled out
46
Food Triggers of FPIP

Most common triggers of FPIP include:
Cow’s milk proteins
 Soy proteins
 Occasionally egg
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Many babies develop the symptoms during
breast-feeding in response to milk and soy
in the mother’s diet
47
Causes and Management of
FPIP
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The cause of FPIP is unknown, but does not
involve IgE, so all tests for allergy are usually
negative
In most cases, avoidance of the offending food
leads to a resolution of the problem
When the baby is breast-fed, elimination of milk
and soy from the mother’s diet is usually enough
to resolve the infant’s symptoms
Occasionally egg can cause the symptoms, in
which case, mother must avoid all sources of egg
in her diet as well
48
Progression of FPIP
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In most cases, the disorder will resolve by the
age of 1 or 2 years
After this age, the offending foods may be
reintroduced gradually, with careful
monitoring for the reappearance of blood in
the baby’s stool
49
Elimination and Challenge
Protocols
Identification of Allergenic Foods


Removal of the suspect foods from the
diet, followed by reintroduction is the
only way to:
 Identify the culprit food components
 Confirm the accuracy of any allergy
tests
Long-term adherence to a restricted diet
should not be advocated without clear
identification of the culprit food
components
51
Food Intolerance: Clinical Diagnosis
Elimination Diet: Avoid Suspect Food
Increase Restrictions
Symptoms Disappear
Symptoms Persist
Reintroduce Foods Sequentially or Double-blind
Symptoms Provoked
Diagnosis Confirmed
No Symptoms
Diagnosis Not Confirmed
52
Elimination and Challenge
Stage 1: Exposure Diary
 Record each day, for a minimum of 5-7 days:
All foods, beverages, medications, and supplements
ingested
 Composition of compound dishes and drinks,
including additives in manufactured foods
 Approximate quantities of each
 The time of consumption

53
Exposure Diary (continued)

All symptoms graded on severity:
 1 (mild);
 3 (moderate)
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Time of onset
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How long they last
 2 (mild-moderate)
 4 (severe)
Record status on waking in the morning.
Was sleep disturbed during the night, and if so,
was it due to specific symptoms?
54
Elimination Diet
Based on:
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Detailed medical history
Analysis of Exposure Diary
Any previous allergy tests
Foods suspected by the patient
Formulate diet to exclude all suspect allergens
and intolerance triggers
Provide excluded nutrients from alternative
sources
Duration: Usually four weeks
55
Selective Elimination Diets
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Certain conditions tend to be associated with specific food
components
Suspect food components are those that are probable triggers
or mediators of symptoms
Examples:

Eczema:
Migraine:
Urticaria/angioedema:
Chronic diarrhea:
Asthma:

Latex allergy:

Oral allergy syndrome:
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Highly allergenic foods
Biogenic amines
Histamine
Carbohydrates; Disaccharides
Cyclo-oxygenase inhibitors
Sulphites
Foods with structurally
similar antigens to latex
Foods with structurally
similar antigens to pollens
56
Few Foods Elimination Diet

When it is difficult to determine which foods
are suspects a few foods elimination diet is
followed
Limited to a very small number of foods and
beverages
 Limited time: 10-14 days for an adult
 7 days maximum for a child

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If all else fails use elemental formulae:

May use extensively hydrolysed formula for a
young child
57
Expected Results of Elimination Diet

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Symptoms often worsen on days 2-4 of
elimination
By day 5-7 symptomatic improvement is
experienced
Symptoms disappear after 10-14 days of
exclusion
58
Challenge

Double-blind Placebo-controlled Food Challenge
(DBPCFC)
 Lyophilized (freeze-dried) food is disguised in
gelatin capsules
 Identical gelatin capsules contain a placebo
(glucose powder)
 Neither the patient nor the supervisor knows the
identity of the contents of the capsules
 Positive test is when the food triggers symptoms
and the placebo does not
59
Challenge (continued)

Drawback of DBPCFC
 Expensive in time and personnel
 Capsule may not provide enough food to
elicit a positive reaction
 Patient may be allergic to gelatin in
capsule
 May be other factors involved in eliciting
symptoms, e.g. taste and smell
60
Challenge (continued)
 Single-blind
food challenge (SBFC)
 Supervisor knows the identity of the
food; patient does not
 Food is disguised in a strong-tasting
“inert” food tolerated by the patient:



lentil soup
apple sauce
tomato sauce
61
Challenge Phase
continued
Open food challenge
 Sequential Incremental Dose Challenge (SIDC)
 Each food component is introduced separately
 Starting with a small quantity and increasing the
amount according to a specific schedule
 This is usually employed when the symptoms
are mild, and the patient has eaten the food in
the past without a severe reaction
Any food suspected to cause a severe or
anaphylactic reaction should only be challenged in
suitably equipped medical facility

62
Open Food Challenge

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

Each food or food component is introduced
individually
The basic elimination diet, or therapeutic diet
continues during this phase
If an adverse reaction to the test food occurs at
any time during the test STOP.
Wait 48 hours after all symptoms have
subsided before testing another food
63
Incremental Dose Challenge
Day 1: Consume test food between meals

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
Morning: Eat a small quantity of the test food
Wait four hours, monitoring for adverse reaction
If no symptoms:
Afternoon: Eat double the quantity of test food eaten in
the morning
Wait four hours, monitoring for adverse reaction
If no symptoms:
Evening: Eat double the quantity of test food eaten in
the afternoon
64
Incremental Dose Challenge
(continued)
Day 2:



Do not eat any of the test food
Continue to eat basic elimination diet
Monitor for any adverse reactions during the
night and day which may be due to a delayed
reaction to the test food
65
Incremental Dose Challenge
(continued)
Day 3:

If no adverse reactions experienced


Proceed to testing a new food, starting Day 1
If the results of Day 1 and/or Day 2 are unclear :
 Repeat Day 1, using the same food, the same test
protocol, but larger doses of the test food
Day 4:

Monitor for delayed reactions as on Day 2
66
Sequential Incremental Dose Challenge

Continue testing in the same manner until all
excluded foods, beverages, and additives have
been tested

For each food component, the first day is the
test day, and the second is a monitoring day for
delayed reactions
67
Maintenance Diet
Final Diet


Must exclude all foods and additives to which a
positive reaction has been recorded
Must be nutritionally complete, providing all
macro and micro-nutrients from non-allergenic
sources

There is no benefit from a rotation diet in
the management of food allergy

A rotation diet may be beneficial when the
condition is due to dose-dependent food
intolerance
69
IMPORTANT NUTRIENTS IN COMMON ALLERGENS
Minerals
Milk
Calcium
+
Phosphorus
+
Egg
Peanut
+
Tree
Nuts
Seeds
Soy
Fish
+
+
+
+
+
+
+
+
Shell
fish
Iron
+
+
+
+
+
+
Zinc
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
Magnesium
Selenium
Potassium
+
+
+
+
Molybdenum
Manganese
Corn
+
+
+
+
+
+
+
+
+
+
Chromium
Copper
Wheat
+
+
+
+
+
+
+
+
+
+
+
70
Vitamins
Milk
Egg
A
+
+
Biotin
+
+
Folate
+
+
+
Niacin
Pantothenic
acid
+
B6 (Pyridoxine)
Nuts
Seeds
Soy
+
Fish
Shellfish
+
+
Wheat
Corn
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
Thiamin
Riboflavin
Peanut
+
+
+
+
+
+
+
+
+
+
+
+
D
+
+
+
+
E
+
+
K
+
+
+
+
+
+
+
+
+
+
B12
+
+
+
+
71
Summary
Food Allergy:
 Immune system response
Food Intolerance:
 Usually metabolic dysfunction
Diagnostic Laboratory Tests:
 Often ambiguous because different physiological
mechanisms are involved in triggering symptoms
72
Summary
Reliable tests for the detection of
adverse reactions to foods:
 Elimination and Challenge
Final diet
Must provide complete nutrition while
avoiding all of the foods and food
components that elicit symptoms on
challenge
73