Egg allergy

• What is Egg Allergy?
• Statistics
• Risk Factors
• Progression
• Symptoms
• Clinical Examination
• How is it Diagnosed
• Prognosis
• Treatment
• References

What is Egg Allergy?

Food allergies can have effects at several different sites in the body, including the mouth, throat, lungs, skin and gastrointestinal tract. Often more than one site in the body is affected at the same time, and the reaction can be generalised, such as anaphylactic shock.

Statistics

Egg allergy is most common in infants and small children, with up to 1 in 20 children developing a (transient) allergy to egg. Fortunately, up to 80% of children with egg allergy will grow out of the allergy before they start school.

Risk Factors

As with most allergies, children with a family or personal history of allergic disease are more likely to develop egg allergy.

Progression

Most children with egg allergy experience their first reaction between 6 and 15 months of age when they are given egg for the first time, often as scrambled egg or custard. Prior to this, exposure to small amounts of egg (during the pregnancy, via breast milk and in other foods) has lead to sensitisation to egg and egg products. Common reactions to egg include skin reactions such as hives and eczema. There have been reports of more serious reactions in patients with egg allergy, however anaphylaxis is rare in comparison to other food allergies such as peanut allergy.

How is it Diagnosed

There are several methods of unorthodox “tests” for food allergy. Examples include cytotoxic food testing, Vega testing, kinesiology, iridology, pulse testing, Alcat testing and Rinkel’s intradermal skin testing. These are unreliable, have no scientific basis and have no useful role in the assessment of allergy.

Prognosis

As noted above, most children with egg allergy outgrow their allergy before they start school, and adults who retain their allergy to egg are usually able to tolerate small amounts of egg in products such as cakes and slices.

Treatment

The best treatment for food allergy is avoidance. Common foods that contain egg or egg products include:

• Malted drinks
• Custards, mousse
• Souffles, meringues
• Glazed rolls or pastries
• Cakes, slices and macaroons
• Some soups and sauces (e.g. Hollandaise)
• Rissoles or meat loaf (used as a binding agent)
• Dessert mixes (waffles, pavlova mix, confectionery etc)

It is important to check the ingredients label on packaged food to determine whether they contain egg or egg products, which are usually under the headings egg yolk, egg white, albumin, egg powder, egg solids, egg lethicin, mayonnaise and ovalbumin. Vaccinations In the past, it has been recommended that children with egg allergy avoid the MMR (measles, mumps and rubella) vaccine. However, it has now been established that this vaccine is safe in people with egg allergy. The vaccine is cultured in a developing chicken embryo rather than a whole egg. The influenza vaccine, however, is cultured in egg and may cause reactions in people with egg allergy.

References

1. ASCIA patient information bulletin. Egg allergy. 2000. Available at: http://www.allergy.org.au/aer/infobulletins/allergy_otherfoods.htm
2. ASCIA patient information bulletin. Food allergy. Australasian Society for Clinical Immunology and Allergy. 2000. Available at: http://www.allergy.org.au/aer/infobulletins/food_allergy.htm
3. James, J. Food Allergies. eMedicine. 2004. Available at: http://www.emedicine.com/med/topic806.htm
4. Patient information sheet. Egg allergy. RPA Allergy unit. 2002. Available at: www.cs.nsw.gov.au/rpa/Allergy/ resources/allergy/eggallergy.pdf
5. Warrell, D. Cox, T. Firth, J. Benz, E. Oxford Textbook of Medicine. 4th ed. 2003. Oxford University Press. Oxford.