2017 NPSS Asheville, NC

Transcription

1 Component Resolved Diagnostics: A Molecular View of Food Protein Sources and Determination of Food Sensitivities John W. Distler, DPA, MBA, MS, FNP-C, FAANP 2017 NPSS Asheville, NC

2 Disclosures John Distler has no financial interests to disclose

3 Learning Objectives Identify common foods that cause allergic reactions in children Develop diagnostic treatment plans based upon the patient s presenting history and signs and symptoms Evaluate the diagnostic work up and develop a detailed management plan for the patient and family

4 John W. Distler, DPA, MBA, MS, FNP-C, FAANP Biography Dean of Nurse Practitioner Tracks, Chamberlain College of Nursing Expertise as a family nurse practitioner at Maryland Asthma and Allergy Consultants in Westminster, Maryland 28 years of experience practicing as a family nurse practitioner in family practice, emergency medicine and asthma, allergy and immunology 16 years of experience as graduate advanced practice nursing faculty/administration Education Doctor of Public Administration, University of Baltimore Master of Business Administration in Health Care Administration, Argosy University Master of Science in Family Nurse Practitioner, State University of New York at Stony Brook Family nurse practitioner certification from the University of California at Davis Medical Center

5 Overview Pathophysiology Signs and Symptoms Differential Diagnosis Food Allergy Testing Treatment Conclusion Questions Outline

6 Overview

7 Allergy Sensitization and the Allergic March INCREASING SYMPTOMS SYMPTOMS LEVEL OFF IgE ROLE OF ALLERGY THERAPY Birth SENSITIZATION Symptoms

8 Atopic Disorders IgE Mediated Allergic rhinosinusitis Asthma Allergic conjunctivitis Atopic dermatitis Urticaria and angioedema Anaphylaxis Insect venom Drug allergy Food allergy Oral allergy syndrome Eosinophilic esophagitis/gastroent eritis

9 Patient Presentation Seasonal Other Disorders Patient Symptoms Perennial Irritants Foods

10 Common Food Allergens Eggs (1.6 percent) Fish (0.4 percent) Tree Nuts (0.4 percent) Milk (2.2 percent) Patient Symptoms Peanuts (0.6 percent) Shell Fish (2.0 percent) Wheat Soy

11 Food Allergies 90 percent of all IgE food allergens are from eight foods Children Milk (casein and lactalbumin), egg (whites-yolks), peanut Soy, fin fish, tree nuts, wheat, shellfish Adults Shellfish, peanuts, tree nuts, fish Lifetime food allergy typically confined to peanuts, tree nuts and shellfish +FH of atopic disease Sampson, H. (2004). Update on food allergy. Current reviews of allergy and clinical immunology, 113(5), pgs

12 Food Allergies Public perception percent (D. Diagnoses) Tolerance Sensitivity Food intolerance (Lactose) True prevalence IgE mediated Adults (4 percent) Infants/children (6-8 percent) Sampson, H. (2004). Update on food allergy. Current reviews of allergy and clinical immunology, 113(5), pgs

13 Food Allergies 2.5 percent of children < 5 years of age (YOA) have milk allergy worldwide Hen egg worldwide 80 percent develop tolerance by 5 years of age; 20 percent develop other food allergies Peanut (depending on geographic location, fish, shellfish may be 3 rd ) Reason for increased prevalence is not known Sampson, H. (2004). Update on food allergy. Current reviews of allergy and clinical immunology, 113(5), pgs

14 Food Allergies Peanut 20 percent of children will outgrow the allergy Clinical intolerance past 5 years of age unlikely to develop tolerance Children with other atopic disorders have higher incidence of food allergy 35 percent with moderate to severe atopic dermatitis have IgE mediated food allergy 6-8 percent of children have food-induced asthma Sampson, H. (2004). Update on food allergy. Current reviews of allergy and clinical immunology, 113(5), pgs

15 Food Allergies Genetic predisposition Protein needs to be seen by the body to start the immune response sensitization New foods are rarely the cause Allergic reaction may occur on second or subsequent exposures Timing of exposure (up to four hours for reaction)

16 Common Food Families Legumes Peanut Navy, kidney, lima, string and soy beans Lentil, peas Tree nuts English, black walnut Almonds, pistachios, cashews, coconut, macadamia, butter nut, pecan, hickory, beechnut and chestnut

17 Common Food Families Mollusks Abalone, mussels, oyster, scallop, clam and squid Crustaceans Crab Lobster, crawfish and shrimp

18 Pathophysiology

19 Food Allergy Pathophysiology Water soluble proteins Genetic predisposition Lack of development of oral tolerance or a breakdown of tolerance in the GI tract Abnormal response of the mucosal immune system to antigens. Sees more antigen than the systemic immune system Results in the production of food specific IgE

20 IgE Development Serum IgE Levels Symptom Development: Rhinitis Asthma Eczema Urticaria N/V Anaphylaxis Body (genetic predisposition) Allergen

21 Food Allergy Pathophysiology IgE Antibodies binds Antigen (allergen) with high-affinity Fce I receptors on Mast cells and Basophils and low-affinity Fce II receptors on macrophages, monocytes, lymphocytes, eosinophils and platelets Mediators are released including histamine, prostaglandins and leukotrienes, cytokines Results in vasodilatation, smooth muscle contraction, mucous secretion and petechial hemorrhage

22 Signs and Symptoms and Differential Diagnoses

23 Food Allergy Symptoms Eczema Generalized pruitis Ocular symptoms Nasal pruitis Bronchospasm Urticaria Headache GI pain Loose stool Vomiting Anaphylaxis

24 Food Allergy Symptoms Severity of reaction based upon Amount Cooked, raw or processed Co-ingestion of other foods Age of patient Degree of sensitization at time of ingestion Rapidity of absorption Taken with exercise Co-morbid conditions (asthma)

25 Food Allergy Testing

26 Intake History Environment Profile Age and type of home Heat and air conditioning Pets Basement Humidifiers Dehumidifiers air cleaners Bedroom / Living areas Plants Atopic History Birth history Formula / Breastfed Food intolerances Age of food introduction Asthma / Bronchitis / Pneumonia Eczema

27 Testing Radioallergosorbent (RAST) tests for Allergen specific IgE (low test sensitivity 80 percent) ImmunoCAP specific IgE improved sensitivity Dermatographism Uncooperative patients Cross reactivity among insect venoms Suspected anaphylaxis Unreliable skin testing Generalized dermatitis Generalized tattoos Inability to d/c antihistamines, H2 blockers or TCAs Schonfeld, J., Berger, W. (2008). Anaphylaxis: Common ways to reduce risk. Consultant, 48(10)

28 Testing IgE The level only determines the likelihood of an allergic reaction, not the severity need to correlate with skin testing and any field reactions Peanut IgE >14, 95 percent chance one will react, but severity is not known IgE- <8, 75 percent chance of a reaction IgE - <2, consider food challenge Schonfeld, J., Berger, W. (2008). Anaphylaxis: Common ways to reduce risk. Consultant, 48(10)

29 Skin Prick Testing Higher sensitivity than ImmunoCAP DC antihistamines, TCAs, H2 blockers, high dose topical steroids 5 days prior 1 st generation (3 days), Hydroxyzine (4 days), 2 nd generation (7 days) Negative reaction likely negative Positive reaction may be false positive (tolerance)

30 Skin Prick Testing Normal saline and histamine controls Prick and intradermal Volar aspect of upper arms or upper back Gold Standard is food ingestion and reaction (100 percent sensitivity)

31 Skin Prick Test

32 Treatment

33 Food Allergy Treatment Dependent upon initial reaction (eczema vs. anaphylaxis) and particular food Positive field reaction/symptoms strict avoidance 3-6 months for mild reactions and certain foods highly variable Longer for moderate to severe reactions Positive IgE/Prick test, but no symptoms small exposure on a weekly basis. Tolerance (low high) AAP Breast feed 4-6 months or use of Hydrolyzed formula at risk infants AAP Food restriction has not been shown to reduce development of food allergies in breast feeding or infancy in the past restrictions were advised ( )

34 Food Allergy Treatment Diet / reaction log Dietary elimination - consider this a treatment with food replacement Oral Food challenges - remains the gold standard (DBPCFC) No medications and no IT

35 Rescue Plans Healthy respect, not a fear Reactions will occur even in very vigilant families College age adults Most deaths occur in teenagers with asthma and fail to give epinephrine early Reactions may occur up to four hours later Benadryl (dissolvable) Prednisone Epinephrine auto-injector

36 Current State of In Vitro and Skin Allergy Testing Current tests define allergen-containing sources, not specific allergenic molecules - More than 50 percent asymptomatic sensitization with positive food tests - Up to 30 percent false positive results in open challenges due to bias The major challenge to allergists is distinguishing crosssensitization from true allergy Recombinant and purified components are pure and reproducible Component and extract preparation tests complement each other Nicolaou, N., et al. (2010). Allergy or tolerance in children sensitized to peanut. Journal of Clinical Immunology. 1, )

37 Peanut Allergy Testing ImmunoCAP allergens and allergen components Component Resolved Diagnostics (CRD) provides a molecular view of the individual protein components of an allergenic source This allows valuable knowledge of IgE sensitization patterns to specific allergen components and cross-reactive allergen components Nicolaou, N., et al. (2010). Allergy or tolerance in children sensitized to peanut. Journal of Clinical Immunology. 1, )

38 Molecular Diagnosis in Peanut Allergy Primary allergy components primary sensitization and specific cause of clinical symptoms Cross-reactive components high degree of structural similarity and more widely distributed causing IgE antibody cross-reactivity Example Birch trees (Betv1) related to proteins in foods, i.e. apples, soy and peanut Nicolaou, N., et al. (2010). Allergy or tolerance in children sensitized to peanut. Journal of Clinical Immunology. 1, )

39 Peanut Allergy Testing CRD test results allow you to make a more informed decision in choosing a treatment strategy for your patients by giving you the ability to assess the risk of allergic reaction, identify cross reactivity patterns and determine a patient s suitability for a particular immunotherapy Ara h (peanut) 1, 2, 3, 6, 8 and 9 Ab Nicolaou, N., et al. (2010). Allergy or tolerance in children sensitized to peanut. Journal of Clinical Immunology. 1, )

40 Risk Assessment With ImmunoCAP Molecular Allergy All available peanut components are needed for a complete risk assessment Nicolaou, N., et al. (2010). Allergy or tolerance in children sensitized to peanut. Journal of Clinical Immunology. 1, )

41 Allergy or Tolerance in Children Sensitized to Peanut: Prevalence and Differentiation Using Component-resolved Diagnostics Study Conclusions: The majority of children considered peanut-sensitized on the basis of standard tests do not have peanut allergy Ara h 2 was the most important predictor of clinical peanut allergy than currently used skin or blood tests Nicolaou, N., et al. (2010). Allergy or tolerance in children sensitized to peanut. Journal of Clinical Immunology. 1, )

42 Conclusions No way to predict future anaphylaxis except with prior history and now CRD Food families not likely a factor Healthy respect, not fear, of food allergy Emergency action plan What can you do? (hint don t order IgE levels)

43 Patient Resources Asthma and Allergy Foundation of America Food Allergy and Anaphylaxis Network American Academy of Allergy, Asthma and Immunology Food Allergy Initiative OKEN= Consortium of Food Allergy Research (CoFAR)

44 References Sampson, H. (2004). Update on food allergy. Current reviews of allergy and clinical immunology, 113(5), pgs Schonfeld, J., Berger, W. (2008). Anaphylaxis: Common ways to reduce risk. Consultant, 48(10) Guidelines for the diagnosis and management of food allergy in the US (2010). National Institute of Allergy and Infectious Disease Nicolaou, N., et al. (2010). Allergy or tolerance in children sensitized to peanut. Journal of Clinical Immunology. 1, ) Centers for Disease Control, (2012). Vaccinations. Retrieved from

45 Thank You Questions? 2017 NPSS ASHEVILLE, NC