Food Allergy & Anaphylaxis

Transcription

1 Food Allergy & Anaphylaxis Selina Gierer, DO Marissa Love, MD University of Kansas Hospital Division of Allergy, Immunology and Rheumatology July 21, 2016 Insert in USA Today December 2010 Generated a movement Education (home, school, restaurants) Resources Passionate opinions Missing uniform clinic recommendations Need accurate information for patients, care givers and providers Objectives To review the differences between food allergy and food intolerance Definitions Prevalence and Natural History Pathophysiology To review useful tips for managing food allergies Emergency Care Prevention Diagnosis 1

2 NIAID Guidelines National Institute of Allergy and Infectious Disease (NIAID) released guidelines in 2010 American Academy of Allergy, Asthma, and Immunology (AAAAI) American College of Allergy, Asthma, and Immunology (ACAAI) 30+ other professional organizations Including AAP, ACFP Federal agencies Consumer groups NIAID Guidelines Created by a variety of experts Expert opinions from all the different areas Evidence based with expert clinical opinion 12,000+ papers thoroughly reviewed Strength based (not radical new data) Provide recommendations for healthcare professionals across a variety of specialties Allergy, pulmonology, gastroenterology Primary care providers NIAID Guidelines Uniform standards for Consensus definition Best clinical management recommendations Treatment Management of anaphylaxis Identification of knowledge gaps Develop research goals for future therapy Published in The Journal of Allergy and Clinical Immunology (AAAAI) 2

3 NIAID Guidelines NIAID created multiple free resources for healthcare professionals, patients, and families Summary version Patient- and family-friendly synopsis Addendum after the LEAP trial Definitions Intolerance your body cannot break down the food for some reason Abdominal pain, gas, vomiting, or diarrhea Eat small amounts do okay Lactose intolerance Allergy your body mistakes that food for something harmful, immune response Can be triggered by eating a microscopic amount or even with touch or inhalation of the particles Definitions Clinical Food Allergy Sensitized and a particular allergen causes reproducible clinical symptoms upon exposure Characteristic symptoms Hives, swelling, difficulty breathing, syncope, anaphylaxis The same patient can have several food allergies 3

4 Definitions Peanuts - legume Tree nuts almonds, cashews, walnuts, Brazil nuts, hazelnuts Shellfish crab, lobster, crayfish, shrimp Mollusks clams, oysters, and scallops Finned fish salmon, tuna, cod, tilapia, etc. Egg baked versus cooked Milk baked versus not Prevalence of Food Allergy Perception by public: 20-25% million Americans (overdiagnosed?) Confirmed allergy (oral challenge) Adults: 1-3.5% Infants/young children: 6-8% More common if you have other allergies Becoming more common in general What do we tell people? We don t really know for sure. 4

5 Estimated Prevalence of Food Allergy Food Children (%) Adults (%) Cow s milk Egg Soy Peanut Tree nut Crustaceans Fish Sampson H. J Allergy Clin Immunol;113:805- Natural History Tolerance 80% children with cow s milk, egg, wheat, and soy allergies will outgrow them prior to the age of 16 20% of children with shellfish, peanut, or tree nut allergy will outgrow this allergy The older the patient is when they develop an allergy, the less likely they will lose that hypersensitivity 5

6 Allergic Reactions Allergic Reactions Respiratory Symptoms Chest tightness, wheezing, cough Gastrointestinal Symptoms Explosive diarrhea, vomiting, cramping pain Cardiovascular Tachycardia, hypotension Anaphylaxis 2 Systemic allergic reaction A serious allergic reaction that is rapid in onset and may cause death NIAID and FAAN (now FARE) Triggers Insect venom, foods, medications, latex Multiple simultaneously 6

7 MYTH: Prior Episodes Predict Future Reactions No predictable pattern Severity depends on Sensitivity of the individual Dose of the allergen Other factors Exercise, concurrent medications, asthma Always be prepared for emergencies Epidemiology of Anaphylaxis Lifetime prevalence: % All triggers Increasing in younger populations Different in subpopulations UK study over 9 years, 2.3 million patients /100,000 in no asthma 50.45/100,000 in asthma cohort Anaphylaxis Venom of stinging insects Wasp, honey bee, fire ant, hornet Inhalants: cat, hamster, horse, grass Natural rubber latex Cross-react with kiwis, bananas, papayas, avocados, chestnuts, potatoes, and tomatoes Spina bifida patients have highest risk for latex allergy Medications 7

8 Anaphylaxis due to Food #1 cause of anaphylaxis in the ER Can be fatal ~ 150 deaths / year Rapid-onset Biphasic in 30% of cases Recurrence of symptoms within 72 hours without repeat exposure Can happen with any food Fatal Food Anaphylaxis Risk factors: Underlying asthma Delayed epinephrine Symptom denial Prior severe reaction Adolescents, young adults Ingestion of a known allergen Key foods: peanuts and tree nuts (~90% of fatalities), fish, shellfish Bock SA, et al. J Allergy Clin Immunol 2001;107: Emergency Treatment Within 5-30 minutes of ingestion, may be longer depending on digestion Always know what to look for: Hives, angioedema Nausea, vomiting, diarrhea Dyspnea, chest or throat tightness Dizziness, confusion, syncope, hypotension Epinephrine is first line therapy 8

9 Emergency Treatment Early recognition is critical Administer epinephrine immediately Do not delay to give steroids or antihistamines! All contacts should know how to use it, especially you! Activate EMS 911 Give anti-histamines (H1 and H2) nebulizer/inhaler treatments, steroids, etc. Then, call emergency contacts Emergency Treatment Seek emergent supervised medical care after using epinephrine We typically observe the patient for about 4-6 hours afterward Biphasic reaction can occur even after the patient looks to be well along the way to recovery Patient should be discharged with epinephrine and education on proper use with avoidance instructions Emergency Treatment Epinephrine auto-injectors (1:1,000) q 15 minutes 0.3 in adults 0.15 if <30kg or have severe CAD/arrhythmias Epinephrine (1:10,000) IV 0.1 mg IV slowly over 5 minutes Mechanism of action: α1 adrenergic vasoconstrictors - decreases mucosal edema, prevents hypotension, increased cardiac output, β1 adrenergic increased force and and rate of cardiac contractions β2 - bronchodilation, decreased release of mediators from mast cells and basophils 9

10 Emergency Treatment Glucagon If on beta blockers and injectable epinephrine is not working Antihistamines Diphenhydramine oral or IV (H1 blockade) Albuterol as needed Particularly if known asthmatic or wheezing Supportive care: IVFs, intubation, etc. Emergency Treatment Delay in use of injectable epinephrine increases risk of death and delayed anaphylaxis 43% get injectable epinephrine from ED visit 12% children receive a second dose 11 Discharge the patient with auto-injectable epinephrine Teach them how to use it Make sure they can afford it 2% physicians knew how to use one! 13 Removal of allergen 6 Do not induce vomiting with food allergy Dangerous, may add to the problem 10

11 Emergency Treatment Steroids May be given in the ER May prevent protracted or biphasic anaphylaxis Cochran analysis no trial evidence in support of use 10 Medication Management No medications can be used to prevent food allergy reactions Key Point: Diphenhydramine will not block anaphylaxis A mild reaction does not predict another mild reaction Consider self-injectable epinephrine for all patients at risk of anaphylaxis Management of Food Allergy Appropriate diagnosis Ensure nutritional needs are being met Proper school diet Ensure schools are aware of the dietary restrictions Education (all surrounding family/friends, etc) ID bracelets Anaphylaxis Emergency Action Plan Most accidental exposures occur away from home Education on presentation of anaphylaxis This frozen dessert could have peanut, tree nut, cow s milk, egg, wheat 11

12 Management of Food Allergy Avoidance is the only effective therapy Complete avoidance of specific food trigger Hidden ingredients in restaurants/homes Labeling issues ( spices, changes, errors) Cross contamination (shared equipment) Food allergy tables and classrooms Foodallergiesrock.com AAAAI Anaphylaxis Wallet Card: Information and Medical Identification 12

13 Allergen Identifcation 2 Clinical history Plausible time frame and exposure history Difficult if unable to assess exposure Novel exposure Reaction can be mild or severe Masked by medications Worsened by underlying asthma Symptoms Difficult to assess in resolving anaphylaxis, children, unconscious/dead patients Allergen Identification 1,2 Confirmation of sensitization: 4-6 weeks later Skin prick tests Large wheal/flare do not always correlate with risk Use fresh foods when available Use the same food, if possible Food extracts are not standardized, some are labile In vitro specific IgE blood testing No correlation of level of IgE and reaction severity Nice to correlate the two 13

14 ImmunoCap Results Food allergy 2 No completely reliable single method for diagnosis History Skin prick tests Size of reaction may provide predictive information Allergen-specific IgE test 50% of patients have positive tests without a clinically correlating reproducible reaction Negative tests helps rules out a true IgEmediated hypersensitivity Risk assessment Age Infants Difficult to recognize: flushing, dysphonia, and loss of sphincter control happen in healthy state Adolescents and young adults High risk of fatality from food Inconsistent avoidance behaviors and usage/carrying of epinephrine auto-injectors Elderly High risk for fatality from insect venom Concomitant disease and medications 14

15 Risk assessment 1,2 Co-morbidities Asthma, cardiovascular disease, severe previous reaction, other allergic conditions (food, exercise, latex, contrast media induced anaphylaxis) Asthma and risk of anaphylaxis vs non-asthmatics 3 UK database review >2.3 million patients, 300 general practices, age years, Jan 01, 1996-Dec 31, 2005 RR in the non-severe asthma group 2.07 (95%CI, ) RR in the severe asthma group 3.29 (95%CI, ) Allergic rhinitis, atopic dermatitis, current use of antihistamines, oral steroids, or antibiotics in the asthma group were at significantly higher risk of anaphylaxis Drug and food allergies Risk assessment 1,2 Co-morbidities Impaired recognition: Psychiatric diseases, autism spectrum disorder, developmental delay, impaired vision or hearing Altered level of mediators: Mastocytosis, benign mast cell hyperplasia Medications: Sedatives, ETOH, recreation drugs (impaired recognition) β-blockers, ACE-I, ARBs (mask severity, block tx response) Strenuous exercise Food is a common co-trigger (wheat) Minimizing Risk 4 Complete medication allergy list Know specifics of the reaction Assess for potential cross-reactivity (ex: tree nuts) Do no harm, using alternatives Educate Patients: diagnosis, avoidance, treatment, ID jewelry, action plans 12 Providers: when to refer, avoid prescribing β- blockers Ensure they have injectable epinephrine Teach everyone how to use it 15

16 Seeking Assistance Food allergy specialist Registered dietitian: ( Food Allergy & Anaphylaxis Network ( Local support groups AAAAI ACAAI Food Allergy Initiative (FAI) National Institute of Allergy and Infectious Disease (NIAID) Take Home Points High index of suspicion for anaphylaxis with: Angioedema Urticaria Respiratory difficulty Hypotension/syncope Possible exposure to allergen Don t be afraid to use injectable epinephrine Remember the biphasic reactions May need to use epinephrine again Thank you for your time! sgierer@kumc.edu - Selina Gierer mlove2@kumc.edu - Marissa Love 16

17 References 1) Simmons FE. Anaphylaxis. Journal of Allergy and Clinical Immunology, Feb 2010; 125 (2 Suppl 2): S ) Simons FE, et al. Risk assessment in anaphylaxis: Current and future approaches. Journal of Allergy and Clinical Immunology, July 2007; 120 (1 supplement): S ) Gonzalez-Perez A, et al. Anaphylaxis epidemiology in patients with and patients without asthma: A United Kingdom database review. Journal of Allergy and Clinical Immunology, 2010; 125: ) Steinberg P. Anaphylaxis: 36 Commonsense Ways to Reduce the Risk. Consultant; August 2009: ) Anaphylaxis diagram. 2.web.britannica.com/eb-media/40/ EFFA24A1.gif 6) Removal of allergen diagram. References 7) Anaphylaxis pathogenesis diagram. 8) Metcalfe DD. Mechanisms of mast cell signaling in anaphylaxis. Journal of Allergy and Clinical Immunology, 2009; 124: ) Vedas PV, et al. Platelet-Activating Factor, PAF Acetylhydrolase, and Sever Anaphylaxis. NEJM, 2008; 358: ) Choo KJL, et al. Glucocorticoids for the treatment of anaphylaxis (Review). The Cochrane Collaboration, The Cochran Library, ) Rudders SA, et al. Multicenter Study of Repeated Epinephrine Treatments for Food-Related Anaphylaxis. Pediatrics, 2010; 125: e ) Kemp AS. Action on anaphylaxis action plans. Journal of Pediatrics and Child Health, March 2010; ) Mehr S, et al. Doctor, how do I use my EpiPen? Pediatric Allergy Immunology, 2007; 18: