A new ImmunoCAP f233 blood test can now determine whether hen’s egg allergy is likely to be severe and persists into adulthood. Once the IgE skin prick test or blood RAST testing show a positive allergy result for eggs, a further test for raised antibodies to the heat-stable  egg protein Ovomucoid (Gal d 1) is very useful for determining if egg allergy will persist.

Ref: Ando H, Moverare R, Kondo Y et al  Utility of ovomucoid-specific IgE concentrations in predicting symptomatic egg allergy. J Allergy and Clin Immunology 2008:122;583-8.

Cow’s milk allergy sufferers may react to one of five different casein or whey proteins in milk. Hence most casein allergic children react to cheese and goats milk while whey allergic children seem to tolerate these products. Heating of milk lowers the allergy potential of the whey components. This explains why whey allergic children seem to tolerate boiled or UHT long-life cow’s milk.

The five principal allergenic proteins in cow’s milk have now been identified as Bos d 4 (alpha-lactalbumin) and Bos d 5 (beta-lactglobulin) in whey, as well as Bos d 6 (Bovine serum albumin), Bos d 8 (Casein) and Bos d lactoferrin (Bovine lactoferrin)

While in Hens’ egg white, there are four different allergenic proteins. These are Gal d 1 (Ovomucoid), Gal d 2 (Ovalbumin), Gal d 3 (Conalbumin) and Gal d 4 (Lysozyme).  One of these could set off an egg allergic reaction in a sensitised individual.

In Peanut we find 9 different Ara h allergens and in Latex there are 13 different Hev b allergens, all capable of triggering a peanut or latex allergic reaction. The Latex Hev b 8 allergen, also called a Profilin is similar to the allergy provoking Profilin found in apple, banana and many other fruits.

This may seem very complicated, but a new range of allergy tests for these specific components are now available.  The tests are called recombinant allergen components and confirm to which protein in a food the individual will react.  Certain allergy provoking proteins such as Profilin, PR-10 proteins, Tropomyosin and Lipid Transfer Protein (LTP) can occur in unrelated food such as Hazelnut and Apple or Latex and Avocado. For example an unsuspecting Latex allergy sufferer may have an acute allergic reaction when eating Avocado, Banana, Kiwi or Chestnut for the first time.

Once the specific allergen is identified on allergy testing, the person can be advised which other foods may cause an adverse allergic reaction

Ref: Steinman H, Native & recombinant allergen components. Phadia AB 2008, ISBN 91-970475-6-2

The influenza and yellow fever vaccines are still cultured on chick egg embryo’s and thus potentially contain egg protein. But the World Health Organisation (WHO) suggests that this is unlikely to be problematic if mildly egg allergic and in those who tolerate egg without anaphylaxis.  In severe egg allergy with anaphylaxis, administration of the conventional influenza and yellow fever vaccinations are contraindicated.

Does the same go for the current Swine Flu (H1N1) influenza vaccine?  I’m informed that Pandemrix currently being promoted to prevent the second wave of the Swine Flu pandemic is also cultured on chick egg embryos. Fortunately there is an alternative Swine Flu vaccine called Celvapan which is not cultured on egg and therefore safe to give to egg allergic individuals. But the Celvapan vaccine does not contain the immunity enhancing adjuvant Squalene and therefore requires 2 doses 3 weeks apart.  Celvapan is also the WHO preferred adjuvant-free Swine flu vaccine to be given during pregnancy.

Annual Flu vaccines are routinely recommended for asthma sufferers as they are generally more prone to viral illnesses, influenza and chest complications.  But Asthma sufferers are also a greater risk group for anaphylaxis if concomitantly egg allergic and inadvertently given the egg cultured flu vaccine. If in doubt, 1/10^th of the vaccine should be administered under medical supervision as a test dose followed by the 9/10th balance if no reaction occurs within 30 minutes.  For detailed advice on egg allergy and Swine Flu vaccinations visit the British Society for Allergy and Clinical Immunology via this link:

http://www.bsaci.org/index.php?option=com_docman&task=doc_download&gid=80