Food AllergyFood Allergy

Againdra K. Bewtra M.B.B.S., M.D.Againdra K. Bewtra M.B.B.S., M.D.

Food Allergy: OutlineFood Allergy: Outline

• DefinitionsDefinitions

• PathophysiologyPathophysiology

• Signs and SymptomsSigns and Symptoms

• Food Allergy - Induced Food Allergy - Induced DiseasesDiseases

• Prevalence and Natural HistoryPrevalence and Natural History

• Diagnosis and ManagementDiagnosis and Management

• PreventionPrevention

Introduction/TermsIntroduction/Terms

• Adverse food reactionAdverse food reaction: any : any aberrant reaction to foodaberrant reaction to food– toxic vs. nontoxictoxic vs. nontoxic

• Food intoleranceFood intolerance: any adverse : any adverse reaction due to reaction due to physiologicphysiologic or or nonimmunologicnonimmunologic mechanism mechanism

• Food allergyFood allergy: any adverse reaction : any adverse reaction due to an due to an immunologicimmunologic mechanism mechanism

Definitions: Adverse Reactions to Definitions: Adverse Reactions to FoodFood

Toxic / PharmacologicToxic / Pharmacologic Non-Toxic / IntoleranceNon-Toxic / Intolerance• Bacterial food Bacterial food

poisoningpoisoning• Heavy metal Heavy metal

poisoningpoisoning• Scromboid fish Scromboid fish

poisoningpoisoning• CaffeineCaffeine• AlcoholAlcohol• HistamineHistamine

A. Nonimmunologic

• Lactase deficiencyLactase deficiency• GalactosemiaGalactosemia• Pancreatic Pancreatic

insufficiencyinsufficiency• Gallbladder / liver Gallbladder / liver

diseasedisease• Hiatal herniaHiatal hernia• Gustatory rhinitisGustatory rhinitis• Anorexia nervosaAnorexia nervosa

• Eosinophilic esophagitisEosinophilic esophagitis• Eosinophilic gastritisEosinophilic gastritis• Eosinophilic gastroenteritisEosinophilic gastroenteritis• Atopic dermatitisAtopic dermatitis• AsthmaAsthma

Definitions: Adverse Reactions to Definitions: Adverse Reactions to FoodFood

IgE-MediatedIgE-Mediated Non-IgE MediatedNon-IgE MediatedB. Immunologic Spectrum

• Oral Allergy Oral Allergy SyndromeSyndrome

• AnaphylaxisAnaphylaxis• UrticariaUrticaria• Allergic RhinitisAllergic Rhinitis• Acute Acute

BronchospasmBronchospasm

• Protein-Induced EnterocolitisProtein-Induced Enterocolitis• Protein-Induced EnteropathyProtein-Induced Enteropathy• Eosinophilic proctitisEosinophilic proctitis• Dermatitis herpetiformisDermatitis herpetiformis• Food-induced Pulmonary Food-induced Pulmonary

HemosiderosisHemosiderosis

PrevalencePrevalence• More common in atopic patientsMore common in atopic patients• One fourth of atopic adults report adverse One fourth of atopic adults report adverse

reaction to food. reaction to food. (Allergy 1978;33:189-196) (Allergy 1978;33:189-196) Will alter Will alter dietary habitsdietary habits

• True prevalence unknownTrue prevalence unknown– Public perception (20-25%)> true prevalencePublic perception (20-25%)> true prevalence– 28% mothers perceive kids to have food allergies28% mothers perceive kids to have food allergies– 8% of these children were DBPCFC positive 8% of these children were DBPCFC positive (pediatrics (pediatrics

1987;79:683-196)1987;79:683-196)

– 1/3 of those with suggestive history have IgE 1/3 of those with suggestive history have IgE mediated food allergymediated food allergy

– 1-2% of adults 1-2% of adults – 8% of children <3 years, (worse if atopic)8% of children <3 years, (worse if atopic)

Pathophysiology: AllergensPathophysiology: Allergens• Any food can cause allergic sxAny food can cause allergic sx• Protein (not fat / carbohydrate)Protein (not fat / carbohydrate)

– 10-70 kD water soluble glycoproteins10-70 kD water soluble glycoproteins– Stable to treatment with heat, acid and proteasesStable to treatment with heat, acid and proteases– Few foods cause most of food allergyFew foods cause most of food allergy– Adults: peanuts, shellfish, tree nuts, fish ->85%Adults: peanuts, shellfish, tree nuts, fish ->85%– Children: eggs, peanut, milk, soy, tree nuts, fish, shellfish, Children: eggs, peanut, milk, soy, tree nuts, fish, shellfish,

wheat ->90%wheat ->90%– Early introduction of foods stimulates excess IgEEarly introduction of foods stimulates excess IgE

• Dyes/flavorings can also elicit allergy symptoms but rareDyes/flavorings can also elicit allergy symptoms but rare– Tartrazine (FD&C yellow dye No.5), found in orange, green Tartrazine (FD&C yellow dye No.5), found in orange, green

or yellow foodor yellow food– Flavorings: nitrites, nitrates, MSG, sulfites Flavorings: nitrites, nitrates, MSG, sulfites

• Single food allergy> multiple food allergySingle food allergy> multiple food allergy• Characterization of epitopes underwayCharacterization of epitopes underway

– Linear Linear vs conformational epitopes conformational epitopes– B-cell B-cell vsvs T-cell epitopes T-cell epitopes

Food Allergy Prevalence in Specific Food Allergy Prevalence in Specific DisordersDisorders

Disorder Food Allergy Prevalence

AnaphylaxisAnaphylaxis 35-55%35-55%

Oral allergy syndromeOral allergy syndrome 25-75% in pollen allergic25-75% in pollen allergic

Atopic dermatitisAtopic dermatitis 37% in children37% in children(rare in adults)(rare in adults)

UrticariaUrticaria 20% in acute20% in acute(rare in chronic)(rare in chronic)

AsthmaAsthma 5-6% in asthmatic or food allergic5-6% in asthmatic or food allergicchildrenchildren

Chronic rhinitisChronic rhinitis RareRare

Pathogenesis of Food AllergyPathogenesis of Food Allergy

• Gut barriersGut barriers: : PhysicalPhysical– defensive barrier against pathogens; tolerate food defensive barrier against pathogens; tolerate food

protein protein – gastric acid, proteolytic enzymes, mucus, peristalsis gastric acid, proteolytic enzymes, mucus, peristalsis

• digest protein to make it less antigenic by: reduce size, alter digest protein to make it less antigenic by: reduce size, alter the structurethe structure

• Gut barrierGut barrier: : Immunologic Immunologic - Dominant response is - Dominant response is tolerancetolerance– GALT [Peyer’s patches, appendix, IELC (Intraepithelial GALT [Peyer’s patches, appendix, IELC (Intraepithelial

lymphocytic cells), LC, plasma cells, mast cells - lymphocytic cells), LC, plasma cells, mast cells - lamina propria, mesenteric LN]lamina propria, mesenteric LN]

– Food ingestionFood ingestionAb release (Ab release (sIgA) (sIgA) (IgG, IgM, IgE)IgG, IgM, IgE)• sIgA: binds protein, forms complexes = decreased absorption sIgA: binds protein, forms complexes = decreased absorption • 2% macromolecules are absorbed-to these oral tolerance 2% macromolecules are absorbed-to these oral tolerance

devel.devel.

Pathogenesis of Food AllergyPathogenesis of Food Allergy

• Dominant response of GALT is Dominant response of GALT is suppression/suppression/tolerancetolerance

• Oral tolerance induction occurs by IELC and GALTOral tolerance induction occurs by IELC and GALT

• IEC: Soluble Ag(food) presented primarily by IELC IEC: Soluble Ag(food) presented primarily by IELC leading to immune suppressionleading to immune suppression– Central APC for immunosuppression in the gutCentral APC for immunosuppression in the gut– Have Have MHC-IIMHC-II and present Ag to and present Ag to CD8CD8+ by (+ by (CD1d)CD1d)

• GALT: Pathogens selectively presented to M cells GALT: Pathogens selectively presented to M cells in the (GALT)in the (GALT)– bacteria, viruses, parasitesbacteria, viruses, parasites– sampled by M cells (Peyer’s patches) sampled by M cells (Peyer’s patches) IgA IgA

Barrier immaturity in the InfantBarrier immaturity in the Infant

• Low basal acid outputLow basal acid output

• Immature intestinal proteolytic activityImmature intestinal proteolytic activity

• Immature microvilli-> Ag transport into Immature microvilli-> Ag transport into IECIEC

• Newborns lack sIgA and IgM in exocrine Newborns lack sIgA and IgM in exocrine secretionsecretion

• Early introduction of numerous food Ag Early introduction of numerous food Ag stimulates excess IgEstimulates excess IgE

Pathogenesis of Food AllergyPathogenesis of Food Allergy

• Genetic predisposition to lack of oral Genetic predisposition to lack of oral tolerancetolerance

• Food-specific IgE bind to Food-specific IgE bind to FcFcRIRI on mast on mast cells/basophils and cells/basophils and FcFcRIIRII on macrophages, on macrophages, monocytes, lymphocytes, eosinophils and monocytes, lymphocytes, eosinophils and plateletsplatelets

• Release of mediators which produce: Release of mediators which produce: vasodilation, smooth muscle contraction, vasodilation, smooth muscle contraction, mucus secretion.mucus secretion.

• Non-IgE: possibly Type III, Type IVNon-IgE: possibly Type III, Type IV

IgE-MediatedIgE-MediatedIgE-receptorIgE-receptor

HistamineHistamine

Protein digestionProtein digestion Antigen processingAntigen processing Some Ag enters bloodSome Ag enters blood

Mast cellMast cellAPC

B cell T cell

TNF-TNF- IL-5IL-5

Non-IgE MediatedNon-IgE Mediated

Pathophysiology: Immune Pathophysiology: Immune MechanismsMechanisms

IgEIgE Non-IgE Acute ChronicNon-IgE Acute ChronicSkinSkin

UrticariaUrticariaAngioedemaAngioedemaAtopic dermatitisAtopic dermatitis

RespiratoryRespiratoryThroat tightnessThroat tightnessRhinitisRhinitisAsthmaAsthma

GutGutVomitVomitDiarrheaDiarrheaPainPain

AnaphylaxisAnaphylaxis

Signs and SymptomsSigns and Symptoms

Clinical Disorders-Signs and Clinical Disorders-Signs and SymptomsSymptoms

• IgE vs. non-IgEIgE vs. non-IgE• GI, cutaneous, respiratoryGI, cutaneous, respiratory• IgE: IgE:

– GI: vomit, diarrhea, painGI: vomit, diarrhea, pain– Resp: throat tightness, rhinitis, asthmaResp: throat tightness, rhinitis, asthma– Skin: urticaria, angioedema, atopic dermatitisSkin: urticaria, angioedema, atopic dermatitis– Other GI Findings: gastric hypotonia, retention of Other GI Findings: gastric hypotonia, retention of

meal, pylorospasm, peristaltic changesmeal, pylorospasm, peristaltic changes

• Non-IgENon-IgE– GI: vomiting, diarrhea, painGI: vomiting, diarrhea, pain– Resp: asthmaResp: asthma– Skin: atopic dermatitisSkin: atopic dermatitis

BirchBirch Apple, apricot, carrot, cherry, kiwi, plumApple, apricot, carrot, cherry, kiwi, plumRagweedRagweed Banana, cucumber, melon, watermelonBanana, cucumber, melon, watermelonGrassGrass Cherry, peach, potato, tomatoCherry, peach, potato, tomato

Oral Allergy SyndromeOral Allergy Syndrome• ? ? Contact urticariaContact urticaria

• Rapid onset, IgE-mediated, rarely progressiveRapid onset, IgE-mediated, rarely progressive

• Oral pruritis, tingling, AE of lips, tongue, palate, Oral pruritis, tingling, AE of lips, tongue, palate, throatthroat

• Usually fresh fruits and vegetablesUsually fresh fruits and vegetables

• Heat labile: cooked forms: no reaction Heat labile: cooked forms: no reaction

• Cause: cross reactive proteins in pollen/food (fruit Cause: cross reactive proteins in pollen/food (fruit

or vegetables)or vegetables) PollenPollen FoodsFoods

• Frequency: ~ 150 deaths / yearFrequency: ~ 150 deaths / year

• Risk: Risk:

– Underlying asthmaUnderlying asthma –– Delayed epinephrine Delayed epinephrine

– Symptom denialSymptom denial –– Previous severe reaction Previous severe reaction

• History: known allergic foodHistory: known allergic food

• Key foods: peanut / nuts / shellfishKey foods: peanut / nuts / shellfish

• Biphasic reactionBiphasic reaction

• Lack of cutaneous symptomsLack of cutaneous symptoms

Fatal Food AnaphylaxisFatal Food Anaphylaxis

Anaphylaxis / Anaphylaxis Anaphylaxis / Anaphylaxis SyndromesSyndromes

• Food-induced anaphylaxis (IgE mediated)Food-induced anaphylaxis (IgE mediated)– Rapid-onset Rapid-onset – Multi-organ system involvementMulti-organ system involvement– Potentially fatalPotentially fatal– Any food, highest risk: peanut, nut, seafoodAny food, highest risk: peanut, nut, seafood

• Symptoms: cutaneous, respiratory, hypotension, vascular Symptoms: cutaneous, respiratory, hypotension, vascular collapse, dysrythmiascollapse, dysrythmias

• Pts usually have the following in common:Pts usually have the following in common:

– Asthma, accidental ingestion of the food allergen,Asthma, accidental ingestion of the food allergen, previous allergic reaction to the same food, immediate previous allergic reaction to the same food, immediate symptomssymptoms

• Food-associated, exercise-induced (usually within 2-4 hours Food-associated, exercise-induced (usually within 2-4 hours after ingestion of food)after ingestion of food)– Associated with a particular foodAssociated with a particular food– Associated with eating any foodAssociated with eating any food

Prevalence of Clinical Cross Prevalence of Clinical Cross Reactivity Among Food “Families”Reactivity Among Food “Families”

Food AllergyPrevalence of Allergy to > 1 Food in Family

FishFish 30% -100%30% -100%

Tree NutTree Nut 15% - 40%15% - 40%

GrainGrain 25%25%

LegumeLegume 5%5%

AnyAny 11%11%

Cross Reactivity of FoodsCross Reactivity of Foods

Disorders Not Proven to be Related to Disorders Not Proven to be Related to Food AllergyFood Allergy

• MigrainesMigraines

• Behavioral / Developmental Behavioral / Developmental

disordersdisorders

• ArthritisArthritis

• SeizuresSeizures

• Inflammatory bowel diseaseInflammatory bowel disease

Natural HistoryNatural History• Dependent on food & immuno-pathogenesisDependent on food & immuno-pathogenesis

• ~ 85% CM, egg, wheat, soy allergy remit by 3 ~ 85% CM, egg, wheat, soy allergy remit by 3 yrs yrs – Declining/low levels of specific-IgE Declining/low levels of specific-IgE

predictive predictive – IgE binding to conformational epitopes IgE binding to conformational epitopes

predictivepredictive

• Allergy to peanut, nuts, seafood typically Allergy to peanut, nuts, seafood typically persistpersist

• Non-IgE-mediated GI allergyNon-IgE-mediated GI allergy– Infant forms resolve 1-3 yearsInfant forms resolve 1-3 years– Toddler / adult forms more persistentToddler / adult forms more persistent

Diagnosis: History / PhysicalDiagnosis: History / Physical

• History: symptoms, timing, History: symptoms, timing, reproducibilityreproducibility– Acute reactions vs chronic diseaseAcute reactions vs chronic disease

• Diet details / symptom diaryDiet details / symptom diary– Specific causal food(s)Specific causal food(s)– ““Hidden” ingredient(s)Hidden” ingredient(s)

• Physical examination: evaluate disease Physical examination: evaluate disease severityseverity

• Identify general mechanismIdentify general mechanism– Allergy vs intoleranceAllergy vs intolerance– IgE versus non-IgE mediatedIgE versus non-IgE mediated

Signs and Symptoms of Food Signs and Symptoms of Food AllergyAllergy

Diagnosis: Laboratory EvaluationDiagnosis: Laboratory Evaluation• Suspect IgE-mediatedSuspect IgE-mediated

– Prick skin tests (fresh extract if oral allergy)Prick skin tests (fresh extract if oral allergy)– RASTRAST

• Suspect non-IgE-mediatedSuspect non-IgE-mediated– Consider biopsy of gut, skinConsider biopsy of gut, skin

• Suspect non-allergic, consider:Suspect non-allergic, consider:– Breath hydrogenBreath hydrogen– Sweat testSweat test– EndoscopyEndoscopy

• Adjunctive testsAdjunctive tests– Endoscopy,/biopsy, stool analysis (heme, leukocytes, Endoscopy,/biopsy, stool analysis (heme, leukocytes,

eosinophils)eosinophils)

• Elimination diet Elimination diet proof of reactivity proof of reactivity• Oral food challenge: DBPCFCOral food challenge: DBPCFC

– Gold standardGold standard

Interpretation of Laboratory TestsInterpretation of Laboratory Tests

• Positive prick test or RASTPositive prick test or RAST– Indicates presence of IgE antibody NOT Indicates presence of IgE antibody NOT

clinical reactivity (~50% false positive)clinical reactivity (~50% false positive)• Negative prick test or RASTNegative prick test or RAST

– Essentially excludes IgE antibody (>95%)Essentially excludes IgE antibody (>95%)• ID skin test with foodID skin test with food

– Risk of systemic reaction & not predictiveRisk of systemic reaction & not predictive– Contraindicated Contraindicated

• Unproven/experimental tests (useless)Unproven/experimental tests (useless)– Provocation/neutralization, cytotoxic tests, Provocation/neutralization, cytotoxic tests,

applied kinesiology, hair analysis, IgG4applied kinesiology, hair analysis, IgG4

CAP-RAST FEIACAP-RAST FEIA

Diagnosis: Elimination Diets and Diagnosis: Elimination Diets and Food ChallengesFood Challenges

• Elimination diets (1 to 6 weeks)Elimination diets (1 to 6 weeks)– Eliminate suspected food(s), orEliminate suspected food(s), or– Prescribe limited “eat only” diet, orPrescribe limited “eat only” diet, or– Elemental dietElemental diet

• Oral challenge testing (MD Oral challenge testing (MD supervised, ER meds available)supervised, ER meds available)– OpenOpen– Single-blindSingle-blind– Double-blind, placebo-controlled Double-blind, placebo-controlled

(DBPCFC)(DBPCFC)

* Unless convincing history warrants supervised challenge* Unless convincing history warrants supervised challenge

Diagnostic Approach: IgE-Mediated Diagnostic Approach: IgE-Mediated AllergyAllergy

• Test for specific-IgE antibodyTest for specific-IgE antibody– Negative: reintroduce food* Negative: reintroduce food* – Positive: start elimination dietPositive: start elimination diet

• Elimination dietElimination diet– No resolution: reintroduce food*No resolution: reintroduce food*– ResolutionResolution

•Open / single-blind challenges to Open / single-blind challenges to “screen”“screen”

•DBPCFC for equivocal open challengesDBPCFC for equivocal open challenges

Diagnostic Approach: Non-IgE-Mediated Diagnostic Approach: Non-IgE-Mediated DiseaseDisease

• Includes disease with unknown mechanismsIncludes disease with unknown mechanisms– Food additive allergy Food additive allergy

• Elimination diets (may need elemental diet)Elimination diets (may need elemental diet)• Oral ChallengesOral Challenges

– Timing/dose/approach individualized for disorderTiming/dose/approach individualized for disorder•Enterocolitis syndrome can elicit shockEnterocolitis syndrome can elicit shock•Enteropathy / eosinophilic Enteropathy / eosinophilic

gastroenteritis may need prolonged gastroenteritis may need prolonged feedings to develop symptomsfeedings to develop symptoms

– DBPCFCs preferredDBPCFCs preferred– May require ancillary testing May require ancillary testing

(endoscopy / biopsy)(endoscopy / biopsy)

Diagnostic Approach to Evaluating Food Diagnostic Approach to Evaluating Food AllergyAllergy

TreatmentTreatment

• Strict avoidanceStrict avoidance– DifficultDifficult

• Of 32 peanut allergic Of 32 peanut allergic patients studied by patients studied by bock et al. Only 8 bock et al. Only 8 were successful at were successful at peanut avoidance peanut avoidance for 5 years.for 5 years.

– ImpossibleImpossible• Peanut allergens on Peanut allergens on

airplanes.airplanes.

• MedicineMedicine– Epi-pen carried at all Epi-pen carried at all

timestimes– Instructed use in officeInstructed use in office– Use and go to E.R.Use and go to E.R.– Observe 4 hoursObserve 4 hours– Risk of fatality Risk of fatality

increases with delay in increases with delay in epinephrine epinephrine administrationadministration

– 1/3 of pts with fatal or 1/3 of pts with fatal or near fatal anaphylaxis near fatal anaphylaxis had biphasic reactionhad biphasic reaction

Treatment: Dietary EliminationTreatment: Dietary Elimination

• Hidden ingredients (peanut in sauces or egg Hidden ingredients (peanut in sauces or egg rolls)rolls)

• Labeling issues (“spices”, changes, errors)Labeling issues (“spices”, changes, errors)

• Cross contamination (shared equipment)Cross contamination (shared equipment)

• ““Code words” (“Natural flavor” may be CM)Code words” (“Natural flavor” may be CM)

• Seeking assistanceSeeking assistance– Registered dietitian: (www.eatright.org)Registered dietitian: (www.eatright.org)– Food Allergy Network Food Allergy Network

(www.foodallergy.org; 800-929-4040)(www.foodallergy.org; 800-929-4040)

Artificial butter flavor, butter, butter fat, Artificial butter flavor, butter, butter fat, buttermilk, casein, caseinates (sodium, calcium, buttermilk, casein, caseinates (sodium, calcium, etc.), cheese, cream, cottage cheese, curds, etc.), cheese, cream, cottage cheese, curds, custard, Half&Halfcustard, Half&Half®®, hydrolysates (casein, milk, , hydrolysates (casein, milk, whey), lactalbumin, lactose, milk (derivatives, whey), lactalbumin, lactose, milk (derivatives, protein, solids, malted, condensed, evaporated, protein, solids, malted, condensed, evaporated, dry, whole, low-fat, non-fat, skim), nougat, dry, whole, low-fat, non-fat, skim), nougat, pudding, rennet casein, sour cream, sour cream pudding, rennet casein, sour cream, sour cream solids, sour milk solids, whey (delactosed, solids, sour milk solids, whey (delactosed, demineralized, protein concentrate), yogurt. demineralized, protein concentrate), yogurt. MAY contain milk: brown sugar flavoring, MAY contain milk: brown sugar flavoring, natural flavoring, chocolate, caramel flavoring, natural flavoring, chocolate, caramel flavoring, high protein flour, margarine, Simplessehigh protein flour, margarine, Simplesse®®..

Example: Milk EliminationExample: Milk Elimination

Treatment: Emergency Treatment: Emergency MedicationsMedications

• Epinephrine: drug of choice for reactionsEpinephrine: drug of choice for reactions– Self-administered epinephrine readily Self-administered epinephrine readily

availableavailable– Train patients: indications/techniqueTrain patients: indications/technique

• Antihistamines: secondary therapy Antihistamines: secondary therapy

• Emergency plan in writingEmergency plan in writing– Schools, spouses, caregivers, mature sibs / Schools, spouses, caregivers, mature sibs /

friendsfriends

• Emergency identification braceletEmergency identification bracelet

Treatment: Follow-UpTreatment: Follow-Up

• Re-evaluate for tolerance periodicallyRe-evaluate for tolerance periodically• Interval and decision to re-challenge:Interval and decision to re-challenge:

– Type of food allergyType of food allergy– Severity of previous symptomsSeverity of previous symptoms– AllergenAllergen

• Ancillary testingAncillary testing– Skin prick test/RAST may remain positiveSkin prick test/RAST may remain positive– Reduced concentration food specific-IgE Reduced concentration food specific-IgE

encouragingencouraging

Pollutants, Tobacco smokePollutants, Tobacco smokeFood Food allergens allergens earlyearly

GenesGenes GenderGender

DamageDamage

InflammationInflammation

InfectionsInfections

SensitizationSensitization

TertiaryTertiary

SecondarySecondaryPrimaryPrimary

??

Allergy PreventionAllergy Prevention

Other TreatmentsOther Treatments

• Possibly effectivePossibly effective• ImmunotherapyImmunotherapy

• Treatment of peanut Treatment of peanut allergy with rush I.T. allergy with rush I.T. Oppenheimer JJ et al. Oppenheimer JJ et al. JACI 1992;90:256-262JACI 1992;90:256-262

• Oral allergen gene Oral allergen gene immunizationimmunization

• MiceMice• Roy et alRoy et al

– Horner et al reported Horner et al reported decreased anaphylaxis decreased anaphylaxis with DNA vaccinewith DNA vaccine

• Generally found Generally found not effectivenot effective– H1 and H2 H1 and H2

antihistaminesantihistamines– Oral Cromolyn Oral Cromolyn

sodiumsodium– KetotofinKetotofin– AntiprostaglandiAntiprostaglandi

nsns

Future Immunomodulatory Future Immunomodulatory TherapiesTherapies

• Recombinant anti-IgE antibodyRecombinant anti-IgE antibody

• Gene (naked DNA) immunizationGene (naked DNA) immunization

• Mutated B-cell epitopesMutated B-cell epitopes

• Minimal T-cell epitopes Minimal T-cell epitopes

• Immune-modulating adjuvants Immune-modulating adjuvants

(ISS)(ISS)

• ProbioticsProbiotics

Reasons for Allergy ReferralReasons for Allergy Referral

• Identification of causative foodIdentification of causative food

• Institution of elimination dietInstitution of elimination diet

• Education on food avoidanceEducation on food avoidance

• Development of action planDevelopment of action plan

• Prevention of other allergiesPrevention of other allergies

Guidelines for Food AllergyGuidelines for Food Allergy

ConclusionConclusion

• 2% of the population have food allergy2% of the population have food allergy

• Children: milk, eggs, peanuts, soy, wheatChildren: milk, eggs, peanuts, soy, wheat

• Adults: peanuts, shellfish, nuts, fishAdults: peanuts, shellfish, nuts, fish

• History and physical History and physical

• IgE and non-IgE mediated conditions existIgE and non-IgE mediated conditions exist

• Dx by elimination and challengeDx by elimination and challenge

• Tx avoidance, education, preparation for Tx avoidance, education, preparation for emergenciesemergencies

• Periodic re-challenge to monitor tolerancePeriodic re-challenge to monitor tolerance