food allergy. adverse food reactions toxic / pharmacologic non-toxic / intolerance bacterial food...
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Food AllergyFood Allergy
Adverse Food Reactions Adverse Food Reactions
Toxic / PharmacologicToxic / Pharmacologic Non-Toxic / IntoleranceNon-Toxic / IntoleranceBacterial food Bacterial food poisoningpoisoningHeavy metal poisoningHeavy metal poisoningScombroid fish Scombroid fish poisoningpoisoningCaffeineCaffeineAlcoholAlcoholHistamineHistamine
Non-immunologic
Lactase deficiencyLactase deficiencyGalactosemiaGalactosemiaPancreatic insufficiencyPancreatic insufficiencyGallbladder / liver Gallbladder / liver diseasediseaseHiatal herniaHiatal herniaGustatory rhinitisGustatory rhinitisAnorexia nervosaAnorexia nervosaIdiosyncraticIdiosyncratic
Adapted from Sicherer S, Sampson H. J Allergy Clin Immunol 2006;117:S470-475.
Eosinophilic Eosinophilic esophagitisesophagitis
Eosinophilic gastritisEosinophilic gastritis
Eosinophilic Eosinophilic gastroenteritisgastroenteritis
Atopic dermatitisAtopic dermatitis
Adverse Food Reactions Adverse Food Reactions
IgE-MediatedIgE-Mediated(most common)(most common)
Non-IgE MediatedNon-IgE MediatedCell-MediatedCell-Mediated
Immunologic
Systemic Systemic (Anaphylaxis)(Anaphylaxis)
Oral Allergy Oral Allergy SyndromeSyndrome
Immediate Immediate gastrointestinal gastrointestinal allergyallergy
Asthma/rhinitisAsthma/rhinitis
UrticariaUrticaria
Morbilliform rashes Morbilliform rashes and flushingand flushing
Contact urticariaContact urticaria
Protein-Induced Protein-Induced EnterocolitisEnterocolitis
Protein-Induced Protein-Induced EnteropathyEnteropathy
Eosinophilic proctitisEosinophilic proctitis
Dermatitis herpetiformisDermatitis herpetiformis
Contact dermatitisContact dermatitis
Sampson H. J Allergy Clin Immunol 2004;113:805-9, Chapman J et al. Ann Allergy Asthma & Immunol 2006;96:S51-68.
Public PerceptionPublic Perception
25% of the population – at least 1 member of 25% of the population – at least 1 member of their family had “food allergy”their family had “food allergy”
Adults surveyed – 20% report they have a Adults surveyed – 20% report they have a “food intolerance” and alter their diet for “food intolerance” and alter their diet for perceived adverse reaction to foodperceived adverse reaction to food
Prevalence – Food Allergy in ChildrenPrevalence – Food Allergy in ChildrenWhat is the est. prevalence under 3 yrs old? What is the est. prevalence under 3 yrs old?
6% (2004)6% (2004)
Fish – 0.1%Fish – 0.1% Shellfish – 0.1%Shellfish – 0.1%
Tree nuts – 0.2%Tree nuts – 0.2%
Soy – 0.4%Soy – 0.4% Wheat – 0.4%Wheat – 0.4%
Food Additives – 0.5-1%Food Additives – 0.5-1%
Peanut – Peanut – 0.8%0.8% (0.5-1%) (0.5-1%)
Egg – 1.3% (2003) young kidsEgg – 1.3% (2003) young kids
Cow’s milk allergy – in 1st yr – 2.5%Cow’s milk allergy – in 1st yr – 2.5%
Asthmatic kids – 6% food induced wheezingAsthmatic kids – 6% food induced wheezing
Mod to severe AD – 35% food allergiesMod to severe AD – 35% food allergies
Prevalence - Food Allergy in AdultsPrevalence - Food Allergy in Adults
What is est. prevalence in adults?What is est. prevalence in adults? 3-4% U.S3-4% U.S. (3.7% - 2004), (2% - 1999). (3.7% - 2004), (2% - 1999)Food additives – 0.01-0.23%Food additives – 0.01-0.23%Fish – 0.4%Fish – 0.4%Tree nut – 0.5%Tree nut – 0.5%Peanut – 0.6% (Total peanut & tree nut 1.1%)Peanut – 0.6% (Total peanut & tree nut 1.1%)Shellfish – (2% - 2004), (0.5% - 1996)Shellfish – (2% - 2004), (0.5% - 1996)Fruits, veggies – common (Fruits, veggies – common (~~5%) but not severe5%) but not severeSesame – increasingly reportedSesame – increasingly reportedAdults with AD – rare food allergyAdults with AD – rare food allergyAdults with asthma – rare food allergyAdults with asthma – rare food allergy
Natural HistoryNatural HistoryMilk allergy – 50% lose reactivity by 1 yrs, Milk allergy – 50% lose reactivity by 1 yrs, 70% by 2 yrs, 85% by 3 yrs70% by 2 yrs, 85% by 3 yrs 35% with milk IgE at 1 year had other food 35% with milk IgE at 1 year had other food
allergies by 3 yrs, 25% had FA at 10 yrs allergies by 3 yrs, 25% had FA at 10 yrs
Egg, soy & wheat – Egg, soy & wheat – 80% resolve by school age80% resolve by school age
Peanut allergy – What percent lose reactivity?Peanut allergy – What percent lose reactivity? 20% by age 5 (1998, 2003), but it may recur20% by age 5 (1998, 2003), but it may recur
Adults can also lose reactivity with avoidanceAdults can also lose reactivity with avoidance
Skin test can remain + but no rxn on DBPCFCSkin test can remain + but no rxn on DBPCFC
CASE: Crustacean Allergy: IgE Towards CASE: Crustacean Allergy: IgE Towards Protein in the Food, NOT Iodine Protein in the Food, NOT Iodine
79 year old man had anaphylaxis to shrimp at age 20, 2579 year old man had anaphylaxis to shrimp at age 20, 25
Doctors told him he was allergic to Doctors told him he was allergic to iodineiodine in seafood in seafood
Avoided seafood, Avoided seafood, iodizediodized salt for years salt for years
Age 70: retirement dinner, hostess picked shrimp out of his portion Age 70: retirement dinner, hostess picked shrimp out of his portion and gave it to him --- ER visit for anaphylaxisand gave it to him --- ER visit for anaphylaxis
At age 79, specific IgE measurement extremely high to shrimp: At age 79, specific IgE measurement extremely high to shrimp: >100 kU/L >100 kU/L
On follow-up after education on avoidance, happily consuming On follow-up after education on avoidance, happily consuming foods with iodized salt because he didn’t have to screen salt foods with iodized salt because he didn’t have to screen salt source any moresource any more
Gastrointestinal Barriers to Ingested Gastrointestinal Barriers to Ingested Food AntigensFood Antigens
Immunologic barriersImmunologic barriers Block penetration of ingested antigens:Block penetration of ingested antigens:
Antigen-specific s-IgA in gut lumenAntigen-specific s-IgA in gut lumen
Clear antigens penetrating GI barrier:Clear antigens penetrating GI barrier:
Serum antigen-specific IgA and IgGSerum antigen-specific IgA and IgG
Reticulo-endothelial system Reticulo-endothelial system
Physiologic barriersPhysiologic barriers Breakdown of ingested antigens:Breakdown of ingested antigens:
Gastric acid and pepsinsGastric acid and pepsins
Pancreatic enzymesPancreatic enzymes
Intestinal enzymesIntestinal enzymes
Intestinal epithelial cell lysozyme Intestinal epithelial cell lysozyme activityactivity
Block penetration of ingested antigens:Block penetration of ingested antigens:Intestinal mucus coat (glycocalyx)Intestinal mucus coat (glycocalyx)
Intestinal microvillus membrane Intestinal microvillus membrane compositioncomposition
Intestinal peristalsisIntestinal peristalsis
Figure 2-15 The mucosal immune system
GALT – induces toleranceGALT – induces tolerance
M Cells overlie Peyer’s Patches (PPs), M Cells overlie Peyer’s Patches (PPs), primarily in distal small intestineprimarily in distal small intestine
M cells have lectin-like receptors which M cells have lectin-like receptors which sample antigens (large) from gut lumensample antigens (large) from gut lumen
Ags taken-up by macrophages and carried Ags taken-up by macrophages and carried to resident T and B cells in PPsto resident T and B cells in PPs
All Ig classes can be produced after oral All Ig classes can be produced after oral antigen, IgM+ B cells primarily switched to antigen, IgM+ B cells primarily switched to IgA+ B cellsIgA+ B cells
Oral ToleranceOral Tolerance
Deletion – only with very high antigen doseDeletion – only with very high antigen dose
AnergyAnergy Intestinal epithelial cells (IECs) – non-professional Intestinal epithelial cells (IECs) – non-professional
APC’s – Class II MHC, but no 2APC’s – Class II MHC, but no 2ndnd signals signals Dendritic cells in PPs (non-inflam environment) express Dendritic cells in PPs (non-inflam environment) express
IL10 and IL4 which favor toleranceIL10 and IL4 which favor tolerance
Figure 10-1 Fates of lymphocytes after encounter with antigens
Failure of Oral Tolerance
Food-specific IgE Abs bind to FcER1 on mast cells and basos
Exposure to Ag - immediate release of vasoactive amines (histamine) – hives, wheezing, shock
Delayed or chronic response - cell mediated or cytokine release (TNF-a, IL-5) and most commonly affect gut
Figure 19-1 Sequence of events in immediate hypersensitivity reactions
Oral Allergy Syndrome/Pollen-Oral Allergy Syndrome/Pollen-Food Allergy SyndromeFood Allergy Syndrome
Mucosal equivalent of Mucosal equivalent of urticariaurticariaItching and swelling of the mouth & oropharynx Itching and swelling of the mouth & oropharynx May lead to refusal of the foodMay lead to refusal of the food
Assoc with rhino-conjunctivitis and pollen allergy Assoc with rhino-conjunctivitis and pollen allergy Birch – apple, cherry, pear, kiwi, carrot, potato, celery, Birch – apple, cherry, pear, kiwi, carrot, potato, celery, hazelnuthazelnutMugwort – Carrot, celery, parsley, fennelMugwort – Carrot, celery, parsley, fennelRagweed – Melon, bananaRagweed – Melon, bananaGrass – Kiwi, watermelon, tomato, potatoGrass – Kiwi, watermelon, tomato, potatoSx may improve with allergy immunotherapySx may improve with allergy immunotherapyCan treat with anti-histaminesCan treat with anti-histamines
Latex-Fruit Latex-Fruit SyndromeSyndrome
30-50% of those with latex allergy are sensitive to 30-50% of those with latex allergy are sensitive to some fruits due to cross-reactive IgEsome fruits due to cross-reactive IgE
Most common fruits: banana, avocado, kiwi, chestnut Most common fruits: banana, avocado, kiwi, chestnut but other fruits and nuts have been reportedbut other fruits and nuts have been reported
Can clinically present as anaphylaxis to fruitCan clinically present as anaphylaxis to fruit
Warn latex-sensitive patients of potential cross-Warn latex-sensitive patients of potential cross-reactivityreactivity
Some fruit-allergic patients may be at risk for latex Some fruit-allergic patients may be at risk for latex allergyallergy
Evaluation of Food AllergiesEvaluation of Food AllergiesHistory:History:
1.1. What food responsible?What food responsible?
2.2. Quantity of foodQuantity of food
3.3. Time courseTime course
4.4. Similar prior symptomsSimilar prior symptoms
5.5. Other factors necessary (exercise, Other factors necessary (exercise, fevers, EtoH)fevers, EtoH)
6.6. When was last reaction?When was last reaction?
Food diaries – causal foods, “hidden” Food diaries – causal foods, “hidden” ingredientsingredients
Skin TestingSkin TestingSkin Prick test – 95% negative predictive value in Skin Prick test – 95% negative predictive value in people > 3 yrs – people > 3 yrs – If negative SPT – food challengeIf negative SPT – food challengeIn kids < 3 years, only 80-85% negative predictive In kids < 3 years, only 80-85% negative predictive valuevalueOnly 50% PPV – IgE present, but they can tolerate Only 50% PPV – IgE present, but they can tolerate the food (atopic derm)the food (atopic derm)Wheal 3 mm greater than neg. Wheal 8 mm.Wheal 3 mm greater than neg. Wheal 8 mm.If positive prick with convincing history of If positive prick with convincing history of anaphylaxis – restrict the foodanaphylaxis – restrict the foodFatalities reported after intradermal testingFatalities reported after intradermal testingFruits, veggies (apples, orange, bananas, potatoes, Fruits, veggies (apples, orange, bananas, potatoes, carrots, celery) – extract not stable – prick-prickcarrots, celery) – extract not stable – prick-prick
TestingTestingOlder RASTs and paper disk 1Older RASTs and paper disk 1stst gen EIAs gen EIAs
Quantitative specific IgE (CAP-FEIA; Quantitative specific IgE (CAP-FEIA; Pharmacia) – 2Pharmacia) – 2ndnd generation – predictive generation – predictive values for reactionsvalues for reactions
Suspect non-IgE – biopsy of gut, skinSuspect non-IgE – biopsy of gut, skin
Suspect non-allergic – sweat, breath H+, Suspect non-allergic – sweat, breath H+, endoscopyendoscopy
Unproven/experimental – Unproven/experimental – provocation/neutralization, cytotoxic tests, provocation/neutralization, cytotoxic tests, kinesiology, hair analysis, IgG4kinesiology, hair analysis, IgG4
Levels of Specific IgE Yielding Predictive Values for CAP-RAST Tests
Food 95 % positivepredictive value
95 % negativepredictive value
Milk 32 0.8
Egg 6 90 % at 0.6
Peanut 15 85 % at <0.35
Soy 50% at 65 2
Wheat 75 % at > 100 5
Fish 20 0.9
Sampson HA, Ho DG. J Allergy Clin Immunol 1997;100:444-51.
Elimination Diets and Food Elimination Diets and Food ChallengesChallenges
Elimination DietsElimination Diets 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 (MD, Crash cart)Oral Challenge (MD, Crash cart) OpenOpen Single-blindSingle-blind Gold Standard to diagnose FAs – DBPCFCGold Standard to diagnose FAs – DBPCFC If DBPCFC is negative, must follow w open If DBPCFC is negative, must follow w open
challenge (1-3% false neg challenge)challenge (1-3% false neg challenge)
AnaphylaxisAnaphylaxis
94%94% of fatal food anaphylaxis involve peanuts or tree nuts (63% peanut, 31% tree)*
Fatalities Due To Anaphylaxis To Fatalities Due To Anaphylaxis To Foods*Foods*
32 fatal cases from 1994-1999 analyzed 32 fatal cases from 1994-1999 analyzed
Peanut accounted for Peanut accounted for 63%63% of fatalities of fatalities Other nuts: Other nuts: 31%31%
AllAll ingestions were ingestions were “accidental”“accidental”84%84% occurred outside of home occurred outside of home
All but 1 had All but 1 had asthmaasthma (97%) (97%)
Epinephrine was Epinephrine was NOT NOT given or was given very given or was given very late in late in 88%88%
**JACIJACI 2001;107:191-1932001;107:191-193
Treatment: EducationTreatment: EducationAnaphylactic SymptomsAnaphylactic Symptoms
Erythema, flushing or pruritusErythema, flushing or pruritus
Urticaria and angioedemaUrticaria and angioedema
Nasal, ocular, and palatal pruritus Nasal, ocular, and palatal pruritus
Sense of impending doomSense of impending doom
Gastrointestinal symptomsGastrointestinal symptoms
Uterine crampsUterine cramps
Dizziness, syncope, loss of Dizziness, syncope, loss of consciousnessconsciousness
Anaphylactic SymptomsAnaphylactic Symptoms
Upper airway obstructionUpper airway obstruction HoarsenessHoarseness Dysphonia (altered voice)Dysphonia (altered voice) Difficulty swallowing.Difficulty swallowing.
Lower airway obstructionLower airway obstruction WheezingWheezing Chest tightnessChest tightness
Treatment: AvoidanceTreatment: Avoidance……Easier Said Than DoneEasier Said Than Done
www.foodallergy.org - FAAN - FAAN25% of labels may not reflect presence of peanut25% of labels may not reflect presence of peanut11
Sensitive patients may react to trace amounts of Sensitive patients may react to trace amounts of peanut (as low as 100 mcg)peanut (as low as 100 mcg)Contact with or inhalation of peanut might occur Contact with or inhalation of peanut might occur on airlineson airlines22
Cross Contamination (shared equipment)Cross Contamination (shared equipment)Hidden ingredientsHidden ingredientsMost common places: Most common places:
Asian restaurants, bakeries and ice cream shops. Asian restaurants, bakeries and ice cream shops. DessertsDesserts
1.1.www.cfsan.fda.gov/~dms/alrgpart.html2. 2. JACI JACI 1999;104:186-91999;104:186-9
Less than 20 kg – Epi Pen Jr Less than 20 kg – Epi Pen Jr (0.15 mg)(0.15 mg)
Over 30 kg – Epi Pen (0.3 mg)Over 30 kg – Epi Pen (0.3 mg)
Between 20-30 kg – Depends Between 20-30 kg – Depends on historyon history
If asthma, h/o anaphylaxis, or If asthma, h/o anaphylaxis, or peanut allergy – Give higher peanut allergy – Give higher (adult) dose 0.3 mg(adult) dose 0.3 mg
Children: 0.01 ml/kg, Children: 0.01 ml/kg, maximum of 0.5 ml maximum of 0.5 ml
Repeated every 5-15 minutes Repeated every 5-15 minutes for two doses and then every 4 for two doses and then every 4 hours (more if needed)hours (more if needed)
Adult: 0.3 ml to 0.5 ml of a Adult: 0.3 ml to 0.5 ml of a 1:1000 dilution 1:1000 dilution subcutaneously or subcutaneously or intramuscularlyintramuscularly
Repeated every 5 to 15 minutes Repeated every 5 to 15 minutes (more PRN)(more PRN)
Epinephrine
Fatal and near-fatal anaphylactic reactions to food Fatal and near-fatal anaphylactic reactions to food in children and adolescents*in children and adolescents*
6 fatal 6 fatal Symptoms 3-30 minutesSymptoms 3-30 minutes Only 2 had epinephrine in first hourOnly 2 had epinephrine in first hour 3 Uniphasic, rapid progression3 Uniphasic, rapid progression 33 Biphasic: Early mild symptoms followed by 1-Biphasic: Early mild symptoms followed by 1-
2 hours asymptomatic; then resp and CV sx2 hours asymptomatic; then resp and CV sx
7 non-fatal7 non-fatal Symptoms within 5 minutesSymptoms within 5 minutes 7/7 received epinephrine within 30 minutes7/7 received epinephrine within 30 minutes 4 Uniphasic: Severe symptoms w/in 30 minutes4 Uniphasic: Severe symptoms w/in 30 minutes 3 Protracted anaphylaxis: Ventilatory support 3 Protracted anaphylaxis: Ventilatory support
and vasopressor meds for > 24 hours (one for 3 and vasopressor meds for > 24 hours (one for 3 weeks!)weeks!)
www.americanmedical-id.comwww.americanmedical-id.com
Food Allergy Action Plan
Other Medications…Other Medications…
H1 receptor antagonist (Diphenhydramine - H1 receptor antagonist (Diphenhydramine - Benadryl)Benadryl) 1 to 2 mg/kg or 25 to 50 mg/dose parenterally1 to 2 mg/kg or 25 to 50 mg/dose parenterally
Ranitidine (Zantac) Ranitidine (Zantac) H2 receptor antagonistH2 receptor antagonist When combined with an H1 type may be useful in When combined with an H1 type may be useful in
reversing reversing hypotension refractory to hypotension refractory to epinephrineepinephrine and intravascular fluid replacement and intravascular fluid replacement
Adult Dose: 50 mg/dose IV/IM q6-8hAdult Dose: 50 mg/dose IV/IM q6-8h
Albuterol, racemic EpinephrineAlbuterol, racemic Epinephrine
Other MedicationsOther MedicationsGlucagon Glucagon 1-5 mg (20-30 mcg/kg) over 5 min by infusion of 5-1-5 mg (20-30 mcg/kg) over 5 min by infusion of 5-
15 mcg/min titrated to clinical response15 mcg/min titrated to clinical response Maintains blood pressure independent of Maintains blood pressure independent of
adrenergic receptors by increasing intracellular adrenergic receptors by increasing intracellular cyclic AMPcyclic AMP
Stimulates release of endogenous catecholaminesStimulates release of endogenous catecholamines
CorticosteroidsCorticosteroids 200 mg hydrocortisone IV200 mg hydrocortisone IV Efficacy of corticosteroids in acute anaphylaxis or in Efficacy of corticosteroids in acute anaphylaxis or in
reducing a late anaphylactic reaction has not been reducing a late anaphylactic reaction has not been clearly established clearly established
Can Food Allergies be Can Food Allergies be Prevented? 50 year debatePrevented? 50 year debate
Who should we target?Who should we target? ““Allergy Genes” – Genome Project – 11q13 Allergy Genes” – Genome Project – 11q13
(IgE receptor), 5q31-33 (cytokine genes), 6p21 (IgE receptor), 5q31-33 (cytokine genes), 6p21 (HLA-D region)(HLA-D region)
Family history – 1 allergic parent – risk Family history – 1 allergic parent – risk atopyatopy 40-60%, 2 allergic parents – 60-80%40-60%, 2 allergic parents – 60-80%
Sensitivity of fam hx in predicting Sensitivity of fam hx in predicting food allergyfood allergy only 45%, specificity is 74%only 45%, specificity is 74%
Cord blood IgE – 26% sensitive, 74% specificCord blood IgE – 26% sensitive, 74% specific Both fam hx plus cord blood IgE – Sensitivity Both fam hx plus cord blood IgE – Sensitivity
56%56%
Maternal AvoidanceMaternal AvoidanceIgE sensitization to food during IgE sensitization to food during gestationgestation is RARE - < 0.3%is RARE - < 0.3%Maternal avoidance of milk and egg during Maternal avoidance of milk and egg during pregnancy not better than infant avoidance pregnancy not better than infant avoidance – not recommended– not recommendedRisk of maternal malnutritionRisk of maternal malnutritionNo harm in recommending peanut No harm in recommending peanut avoidanceavoidance
Primary PreventionPrimary PreventionBreastfeeding – Inconclusive EvidenceBreastfeeding – Inconclusive Evidence Even if Moms avoid allergenic foods – the Even if Moms avoid allergenic foods – the
results can be transientresults can be transient Food allergens can pass into breast milkFood allergens can pass into breast milk Breastmilk can have immunostimulatory or Breastmilk can have immunostimulatory or
immunosuppressive effects on the infant’s immunosuppressive effects on the infant’s intestineintestine
Cytokine content differs in allergenic and non-Cytokine content differs in allergenic and non-allergenic mothersallergenic mothers
Exclusive breastfeeding can decrease infant Exclusive breastfeeding can decrease infant serum IgE, decrease atopic derm and asthmaserum IgE, decrease atopic derm and asthma
Exclusive breastfeeding during 1Exclusive breastfeeding during 1stst 4-6 mos & 4-6 mos & continuation until 1 year is recommendedcontinuation until 1 year is recommended
Lactation Avoidance DietsLactation Avoidance Diets
Conflicting studiesConflicting studies
Most show it is protective to avoid allergenic Most show it is protective to avoid allergenic foods – less atopic derm and food allergiesfoods – less atopic derm and food allergies
Consider avoiding peanuts and tree nutsConsider avoiding peanuts and tree nuts
Most likely don’t need to avoid egg, cow’s milk Most likely don’t need to avoid egg, cow’s milk and fishand fish
Ensure Ensure 1500 mg/day of elemental calcium1500 mg/day of elemental calcium
Delay solids?Delay solids?
High risk of allergy, delay solids to 6 mos oldHigh risk of allergy, delay solids to 6 mos old Finnish study 1983 – 6 mos BF – 14% rate Finnish study 1983 – 6 mos BF – 14% rate
eczema; Food < 6 mos – 35% eczemaeczema; Food < 6 mos – 35% eczema
Delay cow’s milk or dairy to > 1 yearDelay cow’s milk or dairy to > 1 year
Avoid cow’s milk and soy formulas if possibleAvoid cow’s milk and soy formulas if possible Use hydrolyzed hypoallergenic formulaUse hydrolyzed hypoallergenic formula
Delay eggs until 2 yearsDelay eggs until 2 years
Delay peanuts, nuts, and fish until 3 yearsDelay peanuts, nuts, and fish until 3 years
Anti IgE – Xolair (Omalizumab) Anti IgE – Xolair (Omalizumab) Food challenge with encapsulated peanut Food challenge with encapsulated peanut flour – determined thresholdflour – determined threshold4 SQ injections at 4 week intervals4 SQ injections at 4 week intervals2-4 weeks after had repeat challenge2-4 weeks after had repeat challengeIncrease tolerance fromIncrease tolerance from
½ peanut to 9 peanuts½ peanut to 9 peanutsDose dependent Dose dependent
tolerance*tolerance*25% of group showed 25% of group showed
no improvementno improvement
*NEJM 2003;348:986-93*NEJM 2003;348:986-93
Other TherapiesOther Therapies
Traditional Chinese herbs – efficacy in Traditional Chinese herbs – efficacy in murine-model of peanut induced murine-model of peanut induced anaphylaxis – starting human trialsanaphylaxis – starting human trials
Engineered proteins that lack IgE binding Engineered proteins that lack IgE binding sites, engineered chimeric molecules with sites, engineered chimeric molecules with allergen and Fc-gamma, coadministration allergen and Fc-gamma, coadministration of TH-1 promoting adjuvants (CpG and of TH-1 promoting adjuvants (CpG and heat-killed bacteria)heat-killed bacteria)
SummarySummaryPatient history is very importantPatient history is very importantDetermine IgE vs. non-IgE mediated Determine IgE vs. non-IgE mediated Diagnosis by judicious testing, elimination and Diagnosis by judicious testing, elimination and challengechallengeAvoidance/education/preparation for emergencies Avoidance/education/preparation for emergencies are current therapies are current therapies No conclusive studies indicating that manipulation of No conclusive studies indicating that manipulation of the mother’s diet during pregnancy or lactation or the mother’s diet during pregnancy or lactation or the restriction of allergenic foods from the infant’s the restriction of allergenic foods from the infant’s diet will prevent the development of food allergydiet will prevent the development of food allergyPeriodic re-challenge to monitor tolerance as Periodic re-challenge to monitor tolerance as indicated by history, allergen and level of food indicated by history, allergen and level of food specific IgEspecific IgE
ReferencesReferences
Sampson HA. Middleton Ch 89 – Adverse Sampson HA. Middleton Ch 89 – Adverse Reactions to FoodsReactions to FoodsSicherer SH, Sampson HA. Mini-primer. Sicherer SH, Sampson HA. Mini-primer. Ch 9. Food Allergy.J Allergy Clin Immunol Ch 9. Food Allergy.J Allergy Clin Immunol 2006; 117:s470-475.2006; 117:s470-475.Sampson HA. Primer. Ch 9. Food Sampson HA. Primer. Ch 9. Food Allergy.J Allergy Clin Immunol 2003; Allergy.J Allergy Clin Immunol 2003; 111:s540-547.111:s540-547.MKSAP – Allergy and Clinical MKSAP – Allergy and Clinical Immunology. Ch 4 – Food Allergy. Pages Immunology. Ch 4 – Food Allergy. Pages 194-208194-208