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.

– Injectable vs 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 ActNovember 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