Current and novel food allergens: Cross-reactivity and co-sensitisation risks

Food allergy currently affects approximately 10 % of the global population, representing a significant health challenge with no known cure. This chapter describes the current and emerging food allergens, mechanisms of cross-reactivity and co-sensitisation, clinical implications and management, as well as future directions and research gaps. While current allergens such as milk, eggs, peanuts or crustaceans are the primary focus of existing regulations, the rise of novel protein sources, including edible insects, plant-based alternatives, algae and fungi, introduces new risks for de novo sensitisation. A critical distinction is made between cross-reactivity, where IgE recognises homologous proteins across different species (such as tropomyosins in crustaceans and insects) and co-sensitisation, which involves independent immune responses to unrelated allergens. Management relies on a multidisciplinary approach involving strict avoidance, patient education, and the use of epinephrine for emergencies. Advancements in food allergy diagnosis and integrated molecular databases are essential for distinguishing true primary allergies from cross-reactions and for assessing the risks of emerging foods. Furthermore, the chapter emphasises evidence-based prevention, noting that the early introduction of allergenic foods in infancy can significantly reduce the risk of developing allergies. Consistent monitoring and clear labelling remain vital for protecting allergic consumers in an evolving food landscape.