Egg allergy is one of the most prevalent allergies in children, being 1.6 - 3.2% (1). Egg allergy presentation is less common in older children and the adult population, which has prevalence between 1 - 1.6% (1). A child with an egg allergy will have an increased risk of dust mite allergy and asthma in the next couple of years after diagnosis (2). Children with an egg allergy may also develop peanut or other nut allergy (2). The window of opportunity for an egg allergy to develop is up until the first year of life (2). This may start prior to birth as the egg protein can cross the placental barrier and induce specific immune responses in the foetus (1), (2). Egg sensitization can also occur through breast milk (1). The sensitization to egg can be avoided in most cases if the maternal diet is free from egg from
the later part of the pregnancy and for the first year of the child’s life (2). Often the first exposure to egg is when the child commences eating foods, usually after eating baby custard, scrambled egg, touching an egg in the egg carton, or tasting a raw cake mixture (1), (2). In the older children a reaction may occur after the consumption of foods containing uncooked egg, including ice cream, sorbet, mayonnaise, custard, and egg sandwiches (2).
The most common clinical presentation of egg allergy is eczema in children between 6 - 15 months (2).
Other presentations include urticaria, angio-oedema, anaphylaxis, acute vomiting, violent diarrhoea, colitis, with the gastrointestinal symptoms being less defined (1). Most egg allergic children have a natural aversion to egg (2). Highly allergic adults may experience nausea or a flare in eczema (2). Most adults with egg allergy have a natural aversion to egg and are able to eat egg if it is a minor ingredient in a food (2). Hen eggs and eggs from other birds have the same protein and can also illicit reactions in egg allergic individuals (2).
By Julie Albrecht, Consultant Dietician Nutritionist A.P.D.