Critical Knowledge Gaps for Shellfish Allergies: Insights from Global Market Presence and Trade of Shellfish

With the increasing popularity of seafood in human diets, managing allergic reactions to shellfish has become more critical. The objective of this review is a comprehensive analysis of critical knowledge gaps for shellfish allergies based on the relationship of shellfish allergens to global shellfish production and market presence. The methodological approach included the integration of Food and Agriculture Organization (FAO) production data and allergen databases, as well as official legal documents on allergen labeling. According to FAO data, global Mollusca production exceeds that of Crustacea. Despite this, progress in molecular allergen characterization and the development of diagnostic and analytical tools for Mollusca remains underdeveloped. Additionally, food allergen labelling regulations for shellfish are inconsistently applied across countries. Key allergens have been identified in several shellfish species, particularly Crustaceans, but more allergens must be discovered to enhance diagnostic tools. Within Mollusca, Cephalopoda remains understudied, with only one allergen identified despite dominating the shellfish trade. The lack of molecular studies on molluscan allergens hinders the further development of diagnostic tools and accurate allergen detection. Given the high consumption rates and the prevalence of molluscan allergies, large populations are at risk. Therefore, systematic research on molluscan allergens is essential for improving diagnostics, food safety regulations, and public health measures worldwide. Our review summarizes the knowledge gaps of the economically most relevant species of shellfish based on their market presence and trade and provides guidance for further research in the area.