Allergie alimentaire à l'œuf de poule. Données actuelles et perspectives

Together with cow's milk and peanuts, hen's eggs are one of the three principal food allergens affecting children. The symptoms of food allergy (FA) to hen's eggs are above all those due to an IgE-dependant immediate allergy; non-IgE-dependant allergic hypersensitivity is rare. There are at least two phenotypes of FA due to eggs: patients allergic to raw and to cooked eggs (where ovomucoid is usually the cause) and those who react to raw eggs but tolerate cooked eggs. The diagnosis of IgE-dependant FA to egg is easy. It is based on: i) the clinical history; ii) allergy skin prick-tests (SPT); iii) assay for specific serum IgE (IgE); iv) an oral provocation test (OPT) done under close supervision in a specialized center being the diagnostic reference. A combination of the results of the SPT and the serum IgE makes it possible to estimate the threshold values above which the probability of having a positive OPT is high (above 90%). IgE assays for various egg allergens (Gal d 1 to Gal d 6) and microarray assay methods provide means to refine the diagnosis according to its various clinical forms: i) allergy to both raw and cooked eggs; ii) allergy to raw eggs and tolerance to cooked eggs. Overall, the prognosis of FA to eggs is good since three-quarters of the patients outgrow this allergy before 18 years of age. Children allergic to raw eggs but who tolerate cooked eggs have the better prognosis. In cases with persistent hen's egg FA, tolerance induction protocols provide a way to cure this allergy or at least to an increase of the amount of allergen the patient can tolerate. Children who are allergic to eggs are at increased risk for the development of atopic conditions (rhinitis, asthma and eczema) due to other foods or to airborne allergens.