Egg allergy is one of the most common food allergies in children in the UK. It typically affects 2 – 3% of children and is most commonly an IgE mediated reaction. Infants can be sensitised to egg protein even although they have never eaten egg. Egg proteins are known to cross the placenta and are transferred through breast milk. The components of egg are around 70% egg white and 30% egg yolk; with more allergic reactions seen with egg white, although egg yolk can also provoke reactions in sensitive children. Allergic reactions to eggs are also dependant on the state of the egg, whether it is in its raw state, partially or fully cooked. Some children can tolerated cooked egg but not raw or partially cooked.
What are the symptoms?
The most common symptoms of egg allergy are atopic eczema, but also immediate vomiting, diarrhoea and less often anaphylaxis. Although egg allergy is well defined in atopic eczema, the reactions in gastrointestinal problems are less well defined. Parents often report a worsening of gastro-intestinal symptoms in children with established cow’s milk allergy when eggs are introduced during weaning to solids.
Does my child have an egg allergy?
Children who have a less well defined history of egg allergy may have delayed non IgE mediated reactions. Determining whether a child has an egg allergy is usually managed by allergy tests such as skin pricks tests, which are carried out by medical professionals in an Allergy Clinic setting. Detailed dietary assessment may also be helpful with delayed reactions and advice on dietary exclusion followed by reintroduction can determine if reactions are due to egg consumption.