Food Intolerances and Food Allergies: Novel Aspects in a Changing World

Abstract

Despite the rapid progress that has considerably affected most fields of medicine in recent years, many gray areas still exist in our understanding of allergies/hypersensitivities and intolerances to foods. While these pathologies have been widely described and characterized from a clinical point of view, little is known about their pathogenesis, as their mechanisms are often unclear, especially when the clinical manifestations are predominantly gastroenterological. The Food and Agriculture Organization and the World Health Organization, in an ad hoc expert consultation focusing on immunoglobulin E (IgE)-mediated reactions, have identified eight major categories of food allergens: eggs, milk, peanuts, sesame seeds, flour, fish, and shellfish. The reactions to each allergen have different features, making the field of food allergies extremely varied: some, such as egg allergy, tend to improve with age, while others, i.e., fish and seafood allergies, tend to worsen, making their management extremely difficult. The situation is even more complex in the case of hypersensitivities that are not triggered by an IgE-mediated mechanism. Moreover, the objective difficulty of diagnosing and differentiating between food allergies/hypersensitivities and intolerances in some cases should be taken into account. Their clinical presentations are often heterogeneous, embracing a wide spectrum of manifestations: from simple dyspepsia to anaphylaxis and anaphylactic shock [2]. In this scenario, the diagnostic procedures available are often varied, not always standardized and sometimes very long, especially when an elimination diet and a subsequent (double) blind challenge is required. The diagnostic difficulty is mainly linked to non-IgE-mediated reactions. In these cases, diagnostic armamentarium is limited, due to the uncertainties related to the pathogenetic mechanisms, thus making it particularly complex to identify effective and easily repeatable diagnostic biomarkers. Therefore, the aim of this Special Issue is to focus on the field of food allergies/hypersensitivities/intolerances, exploring both the possible pathogenetic mechanisms underlying such conditions and existing management strategies, in the search for possible treatment perspectives.