ORAL INDUCTIONN OF TOLERANCE WITH EXTENSIVELY HEATTED -EGG (HE)
Claver A, Navarro B, Garriga MT, Botey E, NEvot S, Cisteró-Bahíma A
Allergy Department.
USP Instituto Universitario Dexeus.
UAB, Barcelona, Spain
BACKGROUND:
Previous studies suggest that extensive heating and food matrix diminish the allergenicity of egg white proteins, making it possible to be tolerated by some children with egg allergy. We sought to determine the results of our procedure based on a diet incorporating baked egg mixtures in children with egg allergy.
METHODS:
During 2010, 16 children whose clinical characteristics are described in table 1, underwent a first oral food challenge (OFC) with baked egg (starting with gradual doses of cookies and later home-made cake with 4 eggs and breaded chicken with egg and breadcrumbs respectively). In toddlers, we decided to perform a single blind OFC to diminish psychological stress. Subsequently, HE- tolerant patients incorporated HE into their diet (cookies or commercial food products containing egg incorporated daily and coated chicken 2-3 days/week), and were periodically monitored, by phone and hospital follow ups, to identify possible problems during the introduction. All children were challenged with less-heated-egg in the form of hard-boiled egg 3-6 months later.
TABLE 1: BASELINE CLINICAL CHARACTERISTICS
| Gender | 12 Male/4 female |
| Mean Age (y;range) | 6.3(2-16) |
| History of inmediate reaction | 10 (5 anaphilaxys, 2 vomiting, 1 urticaria/angioedema) |
| Sensitizated to egg with strict avoidance diet | 6 |
| Atopic dermatitis (current/resolved) | 10/6 |
| SPT to egg white an ovomucoid (wheal diameter> 8 mm) | 16 |
| Mean Egg white sIgE levels (KU/L; range) | 28.5 (1.37-100) |
| Mean OVM sIgE levels (KU/L; range) | 20.15 (1.05-100) |
RESULTS:
All patients tolerated cookies (2-4 units) in the first OFC, and 13 tolerated cake and/or breaded chicken as well. 3 patients presented mild anaphilaxis with cake and were advised to carry out a dialy cookie intake presenting a negative OFC with breaded chicken 15 days later and negative OFC with cake after 1 month. During the home dosing, 7 cases presented mild symptoms (abdominal pain) with excellent results to oral antihistaminic. Within 6 months of adding HE to their diet, 6 patients presented negative OFC to hard-boiled egg, 10 tolerated hard-boiled yolk and all 16 patients considerably normalized their routines and diminished the risk of severe reactions due to accidental ingestion. Up to this abstract submission day, levels of egg white and ovomucoid sIgE have been re-evaluated in 7 patients, showing an important decrease on both allergens (around 50%).
COMMENTS:
Ingestion of extensively heated egg products is well tolerated and safe, suggesting that strict dietary avoidance of heated egg might not be necessary for the majority of patients with egg allergy. Regular and controlled intake of HE products could not only induce tolerance in egg allergy patients, but might also alter the natural course of egg allergy