Egg allergy occurs in about 2 % of people and is often present in the first year of life.
There may be an association between egg allergy and eczema.
Most reactions to egg are caused by the proteins in egg white .
Symptoms of egg allergy include flushing , tingling of the mouth , urticaria(hives) . Severe symptoms are less common and include vomiting , swelling of the face and throat, shortness of breath and wheezing. Anaphylaxis can also occur. These reactions to egg are usually IgE mediated – i.e. occur within minutes to 2 hours after exposure.
Patients with eczema may experience a worsening of their skin condition while some patients experience gastrointestinal inflammation with reflux, diarrhea, constipation and abdominal pain . These symptoms are as a result of a delayed reaction.
Testing for egg allergy
SPT- skin prick testing may be performed even on young babies by placing egg on the skin and pricking through the drop .
Specific IgE test- This is a blood test which measures the patients antibody response to the egg proteins.
These are available from commercial laboratories,
Elimination / reintroduction diet- this can be useful in the patient with non specific bloating and abdominal discomfort symptoms or constipation .
Management– includes avoidance of the protein and education regarding the reading of food labels. Egg occurs in many foods including: pasta , pastry ,c cakes , biscuits, ice cream, nougat , chocolates, custards etc.Egg is a good source of protein so the advice of a dietician may be useful .
Follow up – this is important on a yearly basis as patients may outgrow their allergy . In fact 66% of egg allergic children will have developed tolerance to all forms of egg b the time they are 16 years old.
Immunizations- important to know is that children with egg allergy should receive all their immunizations . This includes the MMR (measles mumps and rubella) Although they are grown on chick embryos they are generally considered safe in egg allergic individuals.
The influenza and yellow fever rabies vaccine may contain traces of egg protein and should only be given in specialized centers.
It is advisable to patients allergic to hens eggs to avoid eggs from ducks, geese, quails and other birds due to possible cross reactivity.
Mor ethan 70 % of children who are egg allergic may tolerate baked food containing small amounts of extensively heated egg. They should be encouraged to continue consuming baked goods in small amounts as this will help them develop tolerance to egg sooner.
