Transcript Management of Food Allergies in School

Management of Food Allergies in
School
May 20, 2013
Prevalence
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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:
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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 newgeneration, 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
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Hidden ingredients
Labeling (“natural flavors” “natural spices”)
Cross contamination/shared equipment
“may contain”; “made in facility”; made on shared equipment
• Desensitization/Tolerance
– Methods:
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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