In the last decades, the results of studies involving controlled food challenges have provided a reliable scientific basis on the role of foods as a cause of hypersensitivity reactions. Most of these investigations have been focused on paediatric populations, highlighting the role of food allergy in the pathogenesis of atopic dermatitis, identifying foods that most commonly cause allergic reactions, and calling attention to the limited value of skin tests and in vitro assays in the diagnosis of clinical allergy (1). However, less evidence for specific features of adverse reactions to foods in adults has been available. Loveless (2) and Graham et al. (3) verified the association between the ingestion of food and development of symptoms in adults in the 1950s. Further, the remarkable studies conducted by Bernstein et al. (4) and Atkins et al. (5,6) in the early and mid 1980s, definitely confirmed the role of foods as a cause of IgE-mediated allergic reactions in adults and evaluated the relationship between diagnostic procedures and reactivity to food on oral challenge. In 1987, Amlot et al. (7) coined the term, oral allergy syndrome (OAS) to describe the symptoms experienced by a subgroup of patients with positive skin tests to food, typically oral symptoms such as oral irritation and throat tightness, followed in a proportion of patients with systemic symptoms. The OAS was a Ônew termÕ to describe an old featured clinical condition, the association between local oropharyngeal signs and symptoms with the ingestion of foods such as hazelnuts, apples, pears, carrots, celery, and potatoes with allergy to pollen, particularly birch. At that time, Ortolani et al. (8) published a large case series of adult patients who had oral symptoms after ingestion of fresh fruits and vegetables under the title ÔThe oral allergy syndromeÕ. From then on, this term has rapidly gained acceptance, although its exact meaning has not been kept out of some controversy (9, 10). For some years, however, most studies of food allergy in adults were anecdotal reports of anaphylactic reactions after ingestion of a specific food or based mainly on the clinical history supported by positive allergy skin testing and in vitro studies. In the last few years, a number of studies have evaluated adverse reactions to plant-derived foods in adults using DBPCFC models (11-17). Further, by identifying well-characterized clinically allergic patients, these studies have been the basis for detailed immunochemical analysis of allergenic components.The objective of the present review is to provide an overview of the complex nature of the relationship of foods and IgE-mediated allergic reactions in adults, focusing on distinctive features. Following the recommendations of the EAACI Nomenclature Task Force (18), the term food hypersensitivity (FH) will be used to designate an adverse reaction to food, food allergy (FA), when immunological mechanisms have been demonstrated, and IgE-mediated food allergy, if the role of IgE is highlighted.
PrevalenceRecent popul...