Proteins or glycoproteins (not fat or carbohydrate as primary immunogens)
Generally heat resistant, acid stable
Major allergenic foods (>85% of allergy)
Children: milk, egg, soy, wheat, peanut, tree nuts
Adults: peanut, tree nuts, shellfish, fish , fruits and vegetables
commonly stated that “ 90% of food allergies are caused by the “Big 8 ””, this was true for children with atopic dermatitis, not the general population with anaphylaxis. ER studies in US: FRUITS and VEGGIES same % as peanut, crustaceans highest
Emergency Department Visits for Food Allergy (Clark et al. JACI 2004;113:347) Crustaceans: 19% Peanuts: 12% Fruits and Veggies: 12% Are these counted in food allergy prevalence estimates? -NO
CASE: Crustacean Allergy: IgE Towards Protein in the Food, NOT Iodine
79 year old man had anaphylaxis to shrimp at age 20, 25
Doctors told him he was allergic to iodine in seafood
Avoided seafood, iodized salt for years
Age 70: retirement dinner, hostess picked shrimp out of his portion and gave it to him --- ER visit for anaphylaxis
At age 79, specific IgE measurement extremely high to shrimp: >100 kU/L
On follow-up after education on avoidance, happily consuming foods with iodized salt because he didn’t have to screen salt source any more
Biopsy: eos infiltration (mucosa serosa): >15/HPF
Presence of eos doesn’t necessarily invoke food allergy
May affect esophagus to rectum
Response to specific food elimination found in a subset of patients (especially eosinophilic esophagitis): can screen for food allergy with prick/in vitro IgE, patch testing with food is currently under investigation
Disorders Not Proven to be Related to Food Allergy
Dependent upon societal eating and cooking patterns
Prevalence higher in those with:
Certain pollen allergies
Prevalence seems to be increasing
Estimated Prevalence of Food Allergy Sampson H. J Allergy Clin Immunol;113:805-19. Food Children (%) Adults (%) Cow’s milk 2.5 0.3 Egg 1.3 0.2 Soy 0.3-0.4 0.04 Peanut 0.8 0.6 Tree nut 0.2 0.5 Crustaceans Fish 0.1 0.1 2.0 0.4
Prevalence of Clinical Cross Reactivity Among Food “Families” Food Allergy Prevalence of Allergy to > 1 Food in Family Fish 30% -100% Tree Nut 15% - 40% Grain 25% Legume 5% Any 11% Sicherer SH. J Allergy Clin Immunol. 2001 Dec;108(6):881-90.
This frozen dessert could have peanut, tree nut, cow’s milk, egg, wheat
Peanut allergen exposure through saliva: assessment and interventions to reduce exposure. Maloney JM et al. JACI 2006:118:719-24 .
In our UC Davis group of patients with severe tree nut or peanut allergy, 5.3% volunteered that they had a reaction from kissing, sometimes several hours after partner had eaten food. 1/3 in dating situation .
This study: Waiting 60 min, then brushing still did not remove peanut allergen completely
Authors suggest waiting several hours and ingesting a peanut-free meal to be more effective than tooth-brushing or gum-chewing.
Hidden ingredients in restaurants/homes (peanut in sauces,egg rolls)
Restaurants: outsourced dressings/desserts a problem
Woman with near-fatal reaction after patisserie cake
FALCPA won’t help this: “No Nuts in It!” swore the chef
-- Meal served. Told specifically that there were no nuts in it
36 yr old woman with tree nut allergy – peanuts OK Upscale bistro; chef in charge Told waitress of life-threatening allergy – asked to check with chef to make sure dishes she was ordering were safe. Was told, “No problem.” Highly Educated Expert Chef
Ate a few bites and started to have tingling in the mouth
Called the waitress over and asked if there was any way there were nuts in the dish – was told “No” Reaction progressed over minutes, trouble breathing and speaking, used her Epi-Pen, 911 called Hospitalized Jambalaya
AS of January 1, 2006, all food containing “Big Eight Allergens” (cow’s milk, peanut, tree nut, hen’s egg, soy, wheat, fish, crustacean) in the U.S. MUST declare the ingredient on the label in COMMON language. Does NOT apply to non-Big 8 allergens (e.g., sesame).
Label reading used to be very challenging Example: Cow’s Milk Food Allergen Labeling and Consumer Protection Act of 2004 (P.L. 108-282) (FALCPA)
Geographic Unit United States (U.S. Public Law 2004) European Union (European Commission 2003) Australia-New Zealand (Australia New Zealand Food Authority 2001) Canada (pending law, Health Canada 2008) Japan (Ministry of Health 2001) Cow’s milk √ √ √ √ √ Hen’s egg √ √ √ √ √ Wheat √ √ √ √ √ Soy √ √ √ √ Peanut √ √ √ √ √ Tree nuts √ √ √ √ Fish √ √ √ √ Crustacean √ √ √ √ Molluscs √ √ Sesame √ √ √ Mustard seed √ celery √ buckwheat √
Patients with severe food allergy may not receive education on avoidance, self-injectable epinephrine or referral to an allergist at emergency department visits. It is imperative for primary care doctors and allergists to recognize the risks and help patients avoid a future accident. Emergency Department Management of Food Allergy Clark S, et al. J Allergy Clin Immunol 2004;113:347-352.
Chinese herbal remedies (Food Allergy Herbal Formula)
Oral tolerance induction
Induction of tolerance after establishment of peanut allergy by the food allergy herbal formula-2 is associated with up-regulation of IFN- γ . Qu et al. CEA 2007;37:846 .
Murine model of peanut anaphylaxis
Treatment by gavage bid x 6 weeks started AFTER mice allergic completely blocks reactions
Still blocked reactions to peanut 4 weeks after treatment stopped
IL-4, IL-5, IL-13 significantly decreased in mesenteric lymph nodes of treated mice
IFN- γ significantly increased in mesenteric lymph nodes of treated mice
An apparently synergistic combination of phytochemicals is present
Phamacological and immunological effects of individual herbs in the Food Allergy Herbal Formula-2 (FAHF-2) on peanut allergy. Kattan JD et al. Phytotherapy Res 2008;epub ahead of print 4/08
The nine separate “herbs” were individually tested as in the previous studies in the murine model
No single herb offered full protection
One offered statistically signif (but only 4 mice) protection (only ¼ mice had a reaction to peanut): Huang Bai: Phellodendron bark
Huang Bai also reduced plasma histamine levels, but no change in IgE or specific IgG2a levels, whereas FAHF-2 results in decreased IgE and increased IgG2a
Tried a simplified formula with only Huang Bai and 2 other “herbs”, but 2/5 mice had anaphylactic reactions to peanut
Best results with full formula
Food Allergy Initiative and NIH-NIAID Food Allergy Consortium
Funding to Xiu-Min Li and Hugh Sampson at Mt. Sinai.
Food Allergy Herbal Formula 2 is a bitter-tasting decoction/tea. Now, a tablet form has been developed (12 small tablets tid is the human dose). Phase I trial scheduled to start now – announced that patients were now being enrolled at 2008 AAAAI meeting: just tolerability/safety.
They plan to seek FDA approval via Phase II, III trials.