What is a food allergy?
Allergy is a hostile reflex of the organism to one or more foreign molecules ( antigens or allergens), mistakenly considered harmful by the immune system ; in the case of food allergies , the immune-mediated reaction is triggered by some proteins contained in the food itself. Food allergy can be immune-glubulin-E mediated (IgE or “reagine”, most common condition) or NON IgE mediated, and manifest within seconds of exposure to the antigen or appear after a longer period of time.
The ‘ egg is one of the foods of animal origin that most stimulates allergic reaction immune-mediated in susceptible individuals; the relative proteins: ovomucoid , ovalbumin and ovotransferrin , have a high incidence of hypersensitization and are not all easy to inactivate with food processing.
Egg allergy is therefore triggered by the recognition of the peptides mentioned above as harmful molecules for the body; among the readers, some might reason on the fact that, being proteins, to avoid the possibility of any clinical phenomenon linked to their interaction with the immune system, it could be sufficient to subject them to chemical, physical or enzymatic DENATURATION. Well, it is an observation only partially correct, since, in spite of the other, the ovomucoid (protein highly glycosylated dell ‘ ALBUME of egg- HEN ) is a molecule extremely resistant to heat and trypsin digestion ; for this reason, even after cooking , it effectively retains its allergenic capacity.
Allergy to egg protein and chicken meat
According to the Food and Agriculture Organization, egg allergy ranks 3rd among the eight most frequent reactions (responsible for 90% of food allergies); moreover, it has been found that some egg protein allergens are also present in meat , especially chicken, thereby increasing the risk index for allergic reactions .
Egg protein allergy is therefore a very frequent form of hypersensitization; however, being clear that the antigens involved are of three different types, two of which are thermolabile and one thermostable, it is also possible to set a more or less rigorous and specific diet.
Without further ado, an allergic to ovalbumin and ovotransferrin could easily decide to include eggs and chicken meat in their diet, as long as these foods / ingredients are always well cooked and contain sufficiently denatured peptides (in order to exclude the possibility of immune recognition). On the contrary, if the allergy to eggs is characterized by incompatibility towards ovomucoid, the diet must be totally EXCLUSION of foods containing eggs and albumen, allowing the consumption of meat (including chicken), which contains ONLY thermolabile ovalbumin and ovotransferrin. .
- Allergy to ovalbumin and ovotransferrin = exclusion of RAW eggs and meat, the use of COOKED meat and eggs is allowed
- Allergy to ovomucoide = exclusion of both RAW and COOKEDeggs , the use of both RAW and COOKED meat is allowed
- Allergy to ovalbumin, ovotransferrin and ovomucoide = exclusion of both RAW and COOKED eggs, exclusion of RAW meat, the use of COOKED meat is allowed.
All subjects affected by ovomucoid allergy are advised to carefully consult the food labels of manufactured and / or industrially processed products.
List of foods that contain chicken EGGS, ONLY yolk or ONLY egg white : egg pasta , gnocchi with eggs, some ready-made first courses , gratin dishes, shortcrust pastry , sponge cake , custard , other pastry bases, croquettes and others fried , meat loaf, some types of bread such as white bread , egg liquor etc.
NB. Egg allergy is extremely common among the infant population but, fortunately, it represents a form of hypersensitivity with a high probability of regression; Ultimately, it is not only possible, but also frequent, for a subject allergic to eggs to regain the ability to tolerate them over time.