www.WorldAllergy.org Clinical Tips Edited by Rodrigo Rodrigues Alves, MD

From the Editor: is a frequent entity with important implications on quality of life of patients and their families. In this Clinical Allergy Tip, Dr. Ebisawa and Dr. Hayashi provide important information on how to manage patients with suspected allergy in avoiding unnecessary elimination diets and consequently improving their quality of life.

How to improve quality of life for children with hen’s By Motohiro Ebisawa, MD, PhD and Noriko Hayashi (Research Dietician) Sagamihara National Hospital, Clinical Research Center for Allergy and Rheumatology

The allergenicity of heated egg is different from when blood antigen-specific IgE is positive, it that of raw egg. doesn’t necessarily mean that the symptoms of How to minimize handicap of egg allergy food allergy will still appear. Hen’s egg allergy is the most frequent among Antigenicity of the of hen’s egg young children all over the world. In order to The main causative antigen of hen’s egg allergy avoid complete elimination, it is important for is and . The antigenicity hen’s egg allergic patients and guardians to of ovalbumin (OVA) but not ovomucoid (OVM) introduce hen’s egg step by step, such as weakens by heating. OVA is easy to be heated egg with faint contamination of egg denatured by heating to a certain degree. white followed by heated whole egg. In this Patients in whom ovomucoid IgE are way, hen’s egg allergic children and their low, even if the IgE antibodies level is parents can have better quality of life and enjoy high, can often ingest heated egg. 2 However, food products with egg’s unique even if symptoms wouldn’t appear with heated- characteristics. egg ingestion, they might appear with The probability of hen’s egg allergy incomplete heated egg or raw egg ingestion. The probability (possibility of the symptom In addition, the antigenic reduction of OVA is induction) of positive oral food challenge different from OVM by recipe (the temperature, predicted by egg white IgE antibodies measured the length of the heating time and food matrix). by ImmunoCAP ® in Japan has been reported.1 The allergenicity of OVA in food using egg’s thermo-coagulation characteristically decreases The positive-predictive value for diagnosis of 3 food allergy based on egg white IgE antibodies more remarkably than that of OVM, such as measured by ImmunoCAP ® is high, and and hamburger steak. Furthermore, increases as patient age decreases. However, the allergenicity of OVA in cake and biscuit,

WAO Clinical Allergy Tips Copyright World Allergy Organization www.WorldAllergy.org which mixes egg with other ingredients such as yolk with faint contamination of egg white , seems to be clinically much weaker. (STEP 1) to any kind of suspected egg-allergy Steps of oral egg challenges patients (from mild to severe). Then, we introduce heated whole egg as a second step We have two steps of oral food challenges for (STEP 2). the diagnosis of hen’s egg allergy at our hospital. At the first step, we use heated egg

Amount of egg Food Production Method

STEP 1 1 heated-egg yolk with faint Pumpkin cake heated with the contamination of egg white oven ※ (one-10th to one-20th of egg white) STEP 2 1/2 heated whole egg

※ 1000 watts, 90 seconds

Our oral egg challenge protocol

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Oral food challenge of Hen’s egg STEP 1 References------We conduct oral food challenge of hen’s egg 1. Komata T, Ebisawa M et al. The predictive STEP1 for almost all egg allergy patients without relationship of food-specific serum IgE exception as patients and guardians agree. concentrations to challenge outcomes for egg From our experience, as much as eighty percent and varies by patient age. Journal of of egg allergic patients could pass Step 1 Allergy and Clinical 2007; 119: challenge. 4 1272-4. If they could ingest hen’s egg at STEP 1 level, 2. Ando H, Moverare R. Utility of ovomucoid- they could start to try bread, baked specific IgE concentrations in predicting confectionery, and meat substitute (such as symptomatic egg allergy. Journal of Allergy and ham or sausage) which include small amounts Clin Immunology 2008; 122(3): 583-588. of heated white egg. 3. Lemon-Mule H, Sampson HA. Immunologic Challenging hen’s egg STEP 1 leads to the changes in children with egg allergy ingesting improvement of the quality of life of egg allergic extensively heated egg. Journal of Allergy and patients. Clinical Immunology 2008;122(5): 977-983. 4. Ebisawa M, Hayashi N, Sugizaki C, Yanagida N, Imai T. Management of hen's egg allergy in consideration of quality of life ，presented at the XXII World Allergy Congress (WAC 2009) Buenos Aires, Argentina, December 2009.

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