Food Allergies: Diagnosis & Management 2010 NIAID Guidelines

Overview 2010 Guidelines Introduce all potentially allergenic foods around 4-6 months of age, vague risk stratification given Do not restrict maternal diet during pregnancy or lactation for the purpose of preventing FA or AD Diagnose FA based on detailed medical history and targeted confirmatory testing Avoid known allergen ingestion and treat reactions Monitor for tolerance No specific immunotherapy recommendations 2017 Addendum: Prevention of peanut allergy by risk stratified introduction strategies Low and moderate risk, introduce peanuts around 6 months, goal of 3 feedings (6-7 g total) / week High risk individuals (Egg allergy or severe atopic dermatitis), test first, then introduce if able, otherwise avoid What is not known yet Risk stratification strategies for prevention of other food allergies Specific criteria for immunotherapy interventions (peanut and tree nut)

Prevalence of food allergies – Grossly OVER REPORTED However, studies on the incidence, prevalence, and epidemiology of food allergies, especially in the US are lacking.

Food Allergy: Symptoms Erythema Pruritis Hives Angioedema Vomiting / Reflux Strider Cough Wheezing Syncope Anaphylactic Shock Severity of reaction ~ Amount ingested Form (cooked, raw, processed) Co-ingestion of other foods Age of patient Degree of sensitization Rapidity of absorption Empty stomach Alcohol or NSAID ingestion Exercise AD Asthma* Severity of prior reaction is not predictive

Diagnosing Food Allergies Screen for reactions to specific foods, particularly if on more than one occasion and/or a young child 6% of children < age 5 have food allergy Milk, Eggs & Peanut common under age 5 Peanuts, tree nuts and shellfish more common in adolescents & adults Detailed history to identify trigger and other contributing factors Confirm with testing as 50-95% of reported reactions are not true food allergies Recommended diagnostic testing Oral challenge = gold standard Skin Prick testing High sensitivity and negative predictive values, low positive predictive power compared to oral challenge sIGe to allergen (95% predictive values per allergen) SPT and sIGE together can increase the predictive values Discouraged testing Pan allergen testing by SPT or sIGE Total IGE Intradermal or patch testing (systemic rxns, little incremental benefit)

Natural Course & Monitoring Food Allergies Changes in SPT response are not well defined, may stay positive even in the presence of tolerance, wheal shrinkage is thought to correlate with tolerance Drop in sIGE levels over time Oral tolerance is gold standard No data driven recommendations re: frequency of testing, general guidance: Milk, egg soy, wheat – annually Peanut, tree nuts, shell fish every 2-3 years Skip if had recent reaction

LikELihood of Outgrowing various Food Allergies Not as quick as I thought Limited data – generally from follow-up at single clinics, no community based data Generally based on oral tolerance from accidental ingestion and/or defined sIGE level (based on allergen) and then passing oral challenge Egg: Roughly 10% by age 4, 25% by age 6, half by age 8 and 80% by age 12 Milk: 80% by age 5 Wheat: 25% by age 4, half by age 8 and 65% by age 12 Soy: 25% by age 4, half by age 6, 70% by age 10 Peanut Tree Nut

Treating Food Allergies Avoid Urgent & Emergent Treatment of reaction Oral challenges once levels drop < 95% predicted values Immunotherapy options 2010 Guidelines not recommended for anyone New studies: / practice is changing

SUMMARY: So what do we do? Screen for risk of food allergies (severe eczema, or egg allergy and other soft calls – FH: FA) Encourage early introduction of food allergens based on risk level / test if child is high risk for food allergy Screen for observed food reactions Confirm suspected food allergies with diagnostic testing Treat allergic reactions Monitor for reduction in sensitivity Refer if patient if diagnostic uncertainty, patient is a potential candidate for immunotherapy, situation is complicated by multiple allergies, other chronic process (FTT, refractory eczema, severe allergic disease) or parents would like specialist care

Summary: What Not to do Recommend deferred introduction of food allergens across the board Pan test for food allergens Test for cross antigens Restrict multiple food allergens without referring to allergist

Answering Parent questions Why have the recommendations changed so much in the past decade regarding food allergies and introduction of foods? But the WHO says to exclusively breast fed until 6 months of age… Why do we need to do any testing when I’m telling you that they had an allergic reaction to ”x”? If my child has “x” allergy, are they more likely to have other food allergies? Should we test them for other allergies? Can we just test them for everything? Will my child outgrow their “x” allergy? When? How will I know if they outgrow it? Do we really need to get repeat testing?