Food Allergy Update Is There A Relation to Obesity?

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1 Food Allergy Update Is There A Relation to Obesity? Lary Ciesemier, DO FAAAAI FACOI Chair and Associate Professor Internal Medicine Kirksville College of Osteopathic Medicine Allergy Asthma Immunology

2 Objectives Know how to differentiate food allergy and food intolerance. Know the most common allergic foods in adults and children Know the relation between obesity and food allergy Understand how food allergy is diagnosed and treated. Discuss why epinephrine autoinjector needle length may not be satisfactory in obese patients

3 Nothing to disclose Disclosures

4 Introduction/Terms Adverse food reaction-any aberrant reaction to food toxic vs. nontoxic caffeine Food intolerance-any adverse reaction due to physiologic or nonimmunologic mechanism Food allergy-any adverse reaction due to an immunologic mechanism

5 Definitions: Adverse Reactions to Food IgE-Mediated Oral Allergy Syndrome Anaphylaxis Urticaria B. Immunologic Spectrum Eosinophilic esophagitis Eosinophilic gastritis Eosinophilic gastroenteritis Atopic dermatitis Non-IgE Mediated Protein-Induced Enterocolitis Protein-Induced Enteropathy Eosinophilic proctitis Dermatitis herpetiformis

6 Prevalence of food allergy Precise prevalence is unknown, but estimates are: Adults: 1.4% - 2.4% Children < 3 years: ~ 6% Obese children: ~8% Atopic dermatitis (mild/severe): most Increased with obesity Asthmatic children: 6-8% Prevalence depends on: Genetic factors, age, weight, dietary habits Adapted from Sampson HA. Adverse Reactions to Foods. Allergy Principles and Practice. 2003

7 Food allergy in children: International USA & UK Milk Egg Peanut Tree Nuts Seafood FRANCE Egg Peanuts Milk Mustard ITALY Milk Egg Seafood ISRAEL Milk Egg Sesame SINGAPORE Birds Nest Seafood Egg Milk AUSTRALIA Milk Egg Peanuts Sesame

8 Pathophysiology: Allergens Proteins (not fat/carbohydrate) kd glycoproteins - Heat resistant, acid stable Major allergenic foods (>85% of allergy) - Children: milk, egg, soy, wheat - Adult: peanut, nuts, shellfish, fish

9 Obesity and Food Allergy Obesity in children is a/w increased incidence of atopy Total IgE levels higher among obese children Food-specific IgE more common in obese children (atopy) Most common to milk, egg, peanut, shrimp NHANES J Allergy CLIN IMMUNOL May 2009

10 Pathophysiology: Immune Mechanisms IgE-Mediated IgE-receptor Mast cell Histamine B cell Protein digestion Antigen processing Some Ag enters blood APC Non-IgE- Mediated T cell TNF-α IL-5

11 Pollen-Food Syndrome or Oral Allergy Syndrome Clinical features: rapid onset oral pruritus, rarely progressive Epidemiology: prior sensitization to pollens Key foods: raw fruits and vegetables Allergens: Proteins Heat labile (cooked food usually OK) Cause: cross reactive proteins pollen/food Birch Ragweed Grass Mugwort Apple, carrot, celery, cherry, pear, hazelnut Banana, cucumber, melons Melon, tomato, orange Melon, apple, peach, cherry

12 Latex-Fruit Syndrome 30-50% of those with latex allergy are sensitive to some fruits due to cross-reactive IgE Most common fruits: banana, avocado, kiwi, chestnut but other fruits and nuts have been reported Can clinically present as anaphylaxis to fruit Warn latex-sensitive patients of potential crossreactivity Some fruit-allergic patients may be at risk for latex allergy

13 Atopic Dermatitis, Food Allergy and Obesity Atopic Dermatitis Chronic recurrent pruritic inflammatory skin disorder Prevalence increased from 2% 1960, 12-20% 2007 Food allergy common trigger Prolonged obesity is a risk factor for atopic dermatitis JACI Vol 127 No 5.

14 Evaluation: Interpretation of Laboratory Tests Positive prick test or specific IgE Indicates presence of IgE antibody NOT clinical reactivity Negative prick test or specific IgE Essentially excludes IgE antibody (>95% specific)

15 Diagnostic Approach: IgE-Mediated Allergy If test for specific-ige antibody is Negative: reintroduce food* Positive: start elimination diet If elimination diet is associated with No resolution: reintroduce food* Resolution Open / single-blind challenges to screen DBPCFC for equivocal open challenges * Unless convincing history warrants supervised challenge

16 Management

17 Management of Food Allergy 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

18 Robby 8-year-old with peanut allergy since age 2. At age 2, he developed hives around the mouth and swelling after eating peanut candy. At age 6, he had a generalized rash and some difficulty breathing after eating a few bites of a peanut candy. At age 8, he developed an itchy mouth and lower lip swelling after eating a piece of chocolate candy (not known to contain peanut) which resolved by itself without any treatment.

19 What would your prescribed Anaphylaxis Emergency Action Plan be for Robby? 1. Liquid diphenhydramine at start of next reaction; watch for 20 minutes; if it worsens, call Use self-injectable epinephrine at the start of the next reaction, even if only mild symptoms, and call Do nothing; the reaction will go away by itself. 4. Drive to the ER but have the self-injectable epinephrine ready for use in case things get worse.

20 What would your prescribed Anaphylaxis Emergency Action Plan be for Robby? 1. Liquid diphenhydramine at start of next reaction; watch for 20 minutes; if it worsens, call Use self-injectable epinephrine at the start of the next reaction, even if only mild symptoms, and call Do nothing; the reaction will go away by itself. 4. Drive to the ER but have the self-injectable epinephrine ready for use in case things get worse.

21 Key Point: Diphenhydramine will not block anaphylaxis Unfortunately, reaction severity CANNOT be predicted to again be mild with the next episode! In a United Kingdom series of anaphylaxis fatalities, 1/3 of food allergy deaths were in patients with such mild reactions to foods (mainly peanuts/tree nuts) that they had not been prescribed self-injectable epinephrine* Consider prescribing self-injectable epinephrine for all those at risk of anaphylaxis. *Pumphrey RS. Clin Exp Allergy 2000; 30: Pumphrey. J Allerg Clin Immunol 2007; 119:

22 Management: Emergency Treatment of Anaphylaxis Epinephrine: drug of choice Self-administered epinephrine readily available at all times If administered, seek medical care IMMEDIATELY Train patients, parents, contacts: indications/technique Antihistamines: secondary therapy only: WILL NOT STOP ANAPHYLAXIS Written Anaphylaxis Emergency Action Plan Schools, spouses, caregivers, mature sibs / friends Emergency identification bracelet

23 BIPHASIC/LATE-PHASE REACTION Cellular infiltrates: 3 to 6 hours (LPR) Histamine IL-4, IL-6 Eosinophil CysLTs, GM-CSF, TNF-α, IL-1, IL-3, PAF, ECP, MBP Allergen PGs Proteases CysLTs 3 to 6 hours (CysLTs, PAF, IL-5) Basophil Histamine, CysLTs, TNF-α, IL-4, IL-5, IL-6 Monocyte CysLTs, TNF-α, PAF, IL-1 Return of Symptoms Mast cell EPR 15 min (Early-Phase Reaction) Lymphocyte IL-4, IL-13, IL-5, IL-3, GM-CSF

24 PHYSICIAN-SUPERVISED MANAGEMENT OF ANAPHYLAXIS I. Speed is critical: a) assess airway, breathing, circulation b) epinephrine, IM into the anterolateral thigh; 1:1000 dilution, ml (0.01 mg/kg in children); repeat, every 5-15 minutes as necessary. Kemp S and Lockey R. J Allergy Clin Immunol 2002;110:341-8 Simons FER et al. J Allergy Clin Immunol 1998;101:33-7 Simons FER et al. J Allergy Clin Immunol 2001;108:871-3

25 IM vs SQ Epinephrine Intramuscular epinephrine - 2 minutes Subcutaneous epinephrine (5 120) minutes p < Time to C max after injection (minutes) Simons FER: J Allergy Clin Immunol 2004;113:837-44

26 Treatment: Epinephrine Recommended site: vastus lateralis (upper lateral aspect) EpiPen and Twinject may deliver subq in 25% overweight women EpiPen (Dey, Napa, CA) auto-injector has a 22-gauge needle with a needle length of 5 8 and 1 2 in for the senior and junior pens, respectively (30%) children had a skin to muscle surface distance of >5 8" and would not receive epinephrine intramuscularly. Using 1 needle would provide IM delivery to most patients

27 Ann All Imm vol 94, may, 2005

28 ANAPHYLAXIS IN THE EMERGENCY DEPARTMENT Chart review study in 21 North American Emergency Departments Random sample of 678 charts of patients presenting with food allergy Management: - 72% received antihistamines - 48% received systemic corticosteroids - 16% received epinephrine (24% of those with severe reactions) - 33% received respiratory medication (eg. inhaled albuterol) - only 16% received Rx for self-injectable epinephrine at discharge - only 12% referred to an allergist Clark S et al. J Allergy Clin Immunol 2004;347-52

29 Summary Obesity is a risk factor for food allergy IgE is elevated in obese and overweight patients Obese children have a higher risk of developing atopic dermatitis Treating anaphylaxis requires epinephrine, needle length may not be optimal in obese patients Avoidance / education / preparation for emergencies are current therapies Periodic re-challenge to monitor tolerance as indicated by history, allergen, and level of food specific-ige

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