Augustė Juknelytė1, Greta Jankutė 1
1 Lithuanian University of Health Sciences, Academy of Medicine, Faculty of Medicine, Kaunas, Lithuania
Abstract
Food allergy (FA) – an increase of the organism’s immune system response to a food or food supplement. In recent decades, the incidence of FA in the world has increased. The highest incidence is now being recorded in developed countries due to high levels of allergens there. According to various sources, up to 10% of people worldwide may suffer from FA. FA is initiated by the interplay of environmental and genetic factors that determine the manifestations of the disease’s immunopathogenic mechanisms and clinical allergic disorders. In the pathogenesis of allergic reactions, there is an important sensitization that can occur when the allergen enters the body through the gastrointestinal tract, the skin, and less frequently through the respiratory tract. There are three main groups of FA reactions: immunoglobulin E (IgE) mediated, non-IgE mediated and mixed. These reactions cause patients to experience a wide range of symptoms, which complicate the diagnosis of FA. IgE-mediated allergic reactions begin rapidly, within minutes or hours after food intake. The most common clinical manifestations of FA are itching, rashes, digestive, respiratory or cardiovascular symptoms. Non-IgE mediated FA increases the response of an immune system to particular foods or its‘ additives resulting in slow-type reactions. Most of these reactions involve type IV T lymphocytes, but the exact pathogenesis mechanism remains unclear. Symptoms usually appear within a few hours to weeks after the allergen is ingested. Non-IgE mediated food allergy may occur as food protein-induced enteropathy, food protein-induced enterocolitis, food protein-induced proctitis, food-induced pulmonary haemosiderosis. Some FAs may exhibit mixed reactions that have IgE-mediated and non-IgE mediated components. Mixed reactions include gastrointestinal allergies and skin allergies to food, which manifests as atopic dermatitis. The variety of clinical manifestations resulting from different types of reactions adversely affects patients’ quality of life, so making the diagnosis and treatment of this disease is still a major challenge in the daily work of a physician.
Keywords: food allergy, IgE mediated food allergy, non-IgE mediated food allergy, mixed IgE and non-IgE mediated reactions.