Food allergy

Food allergy can be defined as adverse, immunomediated reactions to foods that occur in certain individuals. Food allergy is being increasingly recognized as a public health problem over the last few decades. It has been estimated that up to 10% of children and less than 2% of adults suffer from some type of food allergy. The situation varies in different countries depending on dietary eating pattern. Usually food allergens are proteins or glycoproteins with a molecular weight ranging from 10-70 kDa. Depending on the route of sensitization, food allergy is the result of either genuine reactivity to comestibles through the gastrointestinal tract (class I food allergens) or secondary sensitization to cross-reactive food allergens as a consequence of the initial reactivity to homologous pollen-related allergens (class II food allergens). An allergenic reaction occurs after an initial sensitization to a food allergen where IgE antibodies are produced. Subsequent exposures to the allergen may result in activation/degranulation of mast cells and basophiles (due to cross linking of IgE antibodies by allergens) and release biological mediators (such as histamine) that manifest in observable reaction such as hives, rashes, and anaphylactic shock. Diagnosis of food allergies could be based on in vitro or/and in vivo tests such as clinical history, physical examination, Prick test, elimination of suspected foods from the patient’s diet and different types of food challenge tests. The elimination of food allergens from the diet, pharmacological treatment, immunothrapy and supplementary treatments are the most common treatments. In recent years, the use of recombinant food allergens recruiting genetic engineering, allows highly sensitive detection of sensitization profiles.