Even if allergic to the same food, not all people react to the same protein in the food. There a number of potential allergy provoking proteins found in each food.
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
