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Learn about prevalence, symptoms, diagnosis, and emergency treatments for food allergies in school-age children. Understand food intolerance vs. allergies, common foods causing reactions, and effective prevention strategies.
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Management of Food Allergies in School May 20, 2013
Prevalence • 12 million Americans (4% of population) • 2 million school age children (ages 5-17) • Highest incidence in children under 3 • 29% of children with food allergies also have asthma: increased risk of anaphylaxis
Allergy vs Intolerance • Allergic reaction • Involves the immune system • Common symptoms: • Skin: itching, hives, welts, swelling of face/extremities • Eyes: itchy, watery, swollen • GI: can’t swallow, nausea, vomiting, cramps • CVS: decreased BP, arrhythmia, confusion, fainting, pallor • Neurologic: anxiety, sense of impending doom, lethargy
Allergy vs Intolerance II • Intolerance: • Difficulty digesting a food • Immune system not involved • Enzymatic deficiency (lactose, etc) • Organ insufficiency (gallbladder, liver) • Symptoms: • Headache • Diarrhea/gas/bloating • Rash, not hives
Allergy vs Intolerance III • Toxic/Pharmacologic • Coeliac/gluten enteropathy • Bacterial food poisoning • Scromboid fish poisoning • Caffeine • Alcohol/drugs • Histamine • Systemic mastocytosis • Medications (opioids, contrast dyes)
Food Allergy Prevalence in Specific Disorders • Anaphylaxis: 35 to 55% induced by food allergy • Oral Allergy Syndrome: 25 to 75 % in patients with pollen allergy • Eczema: caused by food in up to 35 to 40 % children; rare in adults • Urticaria: up to 20 % of acute episodes from food; rare in chronic urticaria • Asthma: 5% of asthmatic children have food trigger • Allergic rhinitis: rarely caused by foods
Most Common Foods • 99% of all reactions: • Milk • Soy • Peanuts • Tree nuts • Eggs • Wheat • Fish • Shellfish
Natural History • Outgrown? • Egg, milk, wheat, soy: 85% remit by 3 years…but recent evidence these can persist well into school years • Life long? • Peanuts, tree nuts, shellfish, fish
Diagnosis • Should be based on history of a reaction • Timing in relation to ingestion • Type of symptoms • Other possible sources of symptoms? • Intolerance? Toxic/metabolic/drugs? • RAST vs prick puncture; commercial vs fresh food extract • No ID skin tests with whole food or extracts
Interpretation of Laboratory Tests • Positive prick test or RAST • Indicates presence of IgE (allergic) antibody • Does NOT confirm clinical reactivity: 50 % false positives: patient has allergic antibodies but has blocking antibodies which allow tolerance • Negative prick test or Rast >95% accurate
Fatal Food Anaphylaxis • About 150 deaths per year • Underlying asthma • Failure to use epinephrine • Symptom denial/misreading • Previous severe reaction • Lack of cutaneous symptoms • Biphasic reactions: why we send patient on to emergency department
Predicting Severity of Reaction • Results of skin testing • Results of RAST testing • Class 1 to 6 • Actual counts • History of past reactions • Does each reaction get worse? • Does a mild reaction predict all mild reactions? • Pumphrey RS. ClinExpAllergy.2000 Aug;30 (8):1144-50 • 1/3 food allergy deaths in patients with previous mild reactions, therefore did not have EpiPens
Emergency Treatment I • Epinephrine • Always first treatment • In a patient with a previous documented reaction • Children with positive tests but no previous reaction? Pinczower et al. The effect of provision of an adrenaline autoinjector on quality of life in children with food allergy. JACI 2013; 131:238-240. • Injectablevs oral (!) • Rachid, Ousama et al. Epinephrine absorption from new-generation, taste-marketed sublingual tablets: a preclinical study. Letter to the Editor, JACI 2013; 131: 236-238
Emergency Treatment II • Antihistamines • Secondary therapy • Block symptoms of itch, hives, etc but DO NOT preserve blood pressure • Bronchodilators • If history of asthma, or give even without history if wheeze/cough are observed • Steroids • Block/prevent second phase reaction • Now using ODT prednisolone in emergency kits/plans
Emergency Treatment III • Order of administration: • Epinephrine • Antihistamines • Bronchodilators • Steroids
Treatment by Prevention • Avoidance • Hidden ingredients • Labeling (“natural flavors” “natural spices”) • Cross contamination/shared equipment • “may contain”; “made in facility”; made on shared equipment • Desensitization/Tolerance • Methods: • Oral immunotherapy • Sublingual immunotherapy • Epicutaneous immunotherapy • Feeding extensively heated food (milk, egg) • Modified/recombinant allergen immunotherapty • Chinese herbs • Xolair
Prevention • AVOIDANCE • Research • Xolair • Chinese herbs (FAFH 2) Phase II trial • Peanuts, tree nuts, sesame, fish, shellfish • Oral Immunotherapy • Egg, milk, peanut • Largest experience • Side effects! GI symptoms in 10 – 20%, wheeze, laryngeal edema, uritcaria/angioedema less often
Research • Extensively heated • milk and egg • Sublingual immunotherapy (SLIT) • Kiwi, hazlenut, peach, milk, peanut • Better safety profile than OIT (oropharyngeal symptoms, no epi needed) but smaller amounts tolerated after treatment • Epicutaneous immunotherapy (EPIT) • Milk and peanut • Only local skin reactions • Very limited number of subjects • Modified allergen immunotherapy • Change IgE binding sites but retain modulating sites • Phase I trials; peanut allergy
Tolerance vs Desensitization • Desensitization • During treatment • Increased threshold of dose that causes symptoms DURING treatment • Tolerance/Sustained Unresponsiveness • Long lasting effects of treatment AFTER treatment discontinued • Allows full ingestion of food, not just protection against inadvertent exposure • Ultimate goal of treatment
Legislation and New Jersey • School Access to Emergency Epinephrine Act November 2011 • US Congress House 3627, Senate 1884 • Provides incentive for states to enact laws allowing stock epinephrine in schools • Status in congress?? In NJ? • EpiPen4Schools • August 2012 • 4 free Epi Pen and Epi Pen Jrs • www.EpiPen4Schools.com
Major Review and Sources • S Jones et al. The changing CARE for patients with food allergy. JACI 2013; 131: 3-11. • FAME, St. Louis Children’s Hospital Advocacy and Outreach Department • How to C.A.R.E. for students with food allergies: what educators should know. Free at www.AllergyReady.com • FARE (Food Allergy Research and Education, formerly FAAN and FAI), www.foodallergy.org • AAAAI teaching slide set, Food Allergy