Position document: IgE-mediated allergy to egg protein

Abstract

Egg is the food that most often causes allergy in young Spanish children, with an incidence of 2.4-2.6% in the first 2 years of life. The prevalence of sensitisation and allergy to egg is greater in children with allergy to cow's milk and in those suffering atopic dermatitis. The protein component from egg white is the cause of the allergic response in child. The major allergens in egg white are ovomucoid and ovalbumin. Most of the allergic reactions affect the skin, followed by gastrointestinal and respiratory systems. Egg allergy is one of the most common causes of severe anaphylaxis. The diagnosis of egg allergy is based on the existence of a suggestive clinical history, a positive allergy study and the subsequent application of controlled exposure testing, which represents the gold standard for confirming the diagnosis. The treatment of egg allergy is based on the avoidance of egg protein intake. A subgroup of egg-allergic patients are tolerant to cooked egg. In these cases, only uncooked egg must necessarily be avoided. Maintaining a diet with strict egg avoidance is difficult, and transgressions are relatively common. The patient, family, and school environment should receive education and training in the avoidance of egg and in the management of possible allergic reactions. With an avoidance diet, up to 15-20% of children will remain allergic and the severity of the reactions will increase over the years. In these more severe cases of egg-allergy, it becomes more difficult to adhere to the avoidance diet over the years, with a significant decrease in patient quality of life. Oral tolerance induction can be regarded as a therapeutic option for IgE-mediated egg allergy. The anti-IgE, omalizumab, might become another genuine therapeutic option for food allergy, not only to prevent allergic reactions after a contact with egg, but also as a complementary treatment to oral tolerance induction for egg allergy, with the purpose of reducing adverse reactions. The administration of influenza vaccine to children with egg allergy is safe in children that do not manifest severe reactions after egg intake, and in children who tolerate cooked egg. The triple viral vaccine (MMR) can be given to egg-allergic children in their usual vaccination centre, with no added risk. Different medicinal products can be formulated with egg proteins, and therefore should be avoided in children with egg allergy.

Food Allergy and the Oral Immunotherapy Approach

“…However, in the case of food allergy, evidence has been presented which relates to other routes that are responsible for allergen sensitization. In this sense, it was found that more than one-half of the patients with egg allergy developed clinical manifestations between 6 and 12 months of age, when egg was first introduced into the diet (Martorell et al 2013). Similarly, the majority of children develop peanut or tree nut allergy following their first ingestion (Brough et al 2013;Ewan 1996;Lack et al 2003).…”

Vegetable Proteins: Non-sensitizing Encapsulation Agents for Bioactive Compounds

“…In the curd, four caseins account for ~80% of milk proteins. The remaining 20% of the proteins, are globular proteins (e.g., lactalbumin, lactoglobulin, and bovine serum albumin), and are found in whey and egg proteins from both components (i.e., yolk and egg white) causing sensitization [30].…”

“…In the digestive system, these barriers are composed of two groups: (i) non-immunological such as the gastric acid, pancreatic enzymes, intestinal enzymes, mucus, the membrane of the micro villi, the mucosal layer and intestinal peristalsis), and (ii) immunological, such as IgA, IgE, IgM, IgG, lymphocytes, macrophages, Peyer's patches, intestinal secretory IgA and secre tory IgA in breast milk [30]. Usually, when the immune system recognizes food proteins as a foreign body, immunoregulatory mechanisms are established that lead to the acquisition of tolerance.…”

“…Usually, when the immune system recognizes food proteins as a foreign body, immunoregulatory mechanisms are established that lead to the acquisition of tolerance. Alterations in these regulatory mechanisms alter the induction of tolerance, result ing in food allergy [30]. An allergy reaction require a complex interaction between the pro tein and the immune system [26].…”

“…Thus, IgE are able to bind a specific receptor on the sur face of mast cells and basophils, when two or more of these captive IgE molecules bind to their specific antigen, becoming cross-linked on the surface of the cell [26]. Once the allergens pen etrate the mucosal barriers and bind to the IgE of mast cells and basophils, these cells release mediators that cause vasodilatation, smooth muscle contraction and mucosal secretion, giving rise to the typical symptoms of immediate hypersensitivity (Annex 1) [30].…”