[Allergy to egg proteins in children]

Food allergy prevalence has increased during the last years, affecting 15-20% of children, in this case, egg allergy affects from 0.5-2.5%. Most of the egg allergic reactions are type I or IgE mediated antibodies against egg proteins. Five major proteins have been identified: ovomucoid (Gal d1), ovoalbumin (Gal d2), ovotransferrin (Gal d3), lysozyme (Gal d4) and albumin (Gal d5). Ovomucoid protein, which is found in the egg white, is heat resistant and enzyme resistant. This protein is the most allergenic and the most common in egg composition. Clinical diagnosis requires a detailed questionnaire. Skin prick test or Ige specific diagnosis are made as first choice. Skin prick tests are quick and useful to determine the presence of IgE specific antibodies to egg. Specific IgE for egg can be measured using standarized IgE studies in vitro, making a quantitative measure. Traditionally with the clinical history a diagnosis can be made. Standarized oral double blinded-placebo controlled challenge continues to be the gold standard for food allergy diagnosis. The identification and elimination of egg proteins from the diet is the primary treatment and the only one validated to this food, but there are more studies needed to stablish protocols for each specific egg allergen before the oral inmunotherapy becomes a routine practice.