Clinical and Immunological Features in Limpet (Patella sp.) Allergy in Subtropical Areas: A New Trigger for Food Anaphylaxis

Seafood is a crucial source of nutrients, with global consumption steadily increasing. Among seafood-related allergies, shellfish are a significant cause of food allergy and anaphylaxis worldwide, affecting approximately 0.5–2.5% of the general population. While the majority of existing research has focused on crustaceans, allergic reactions to mollusks, including their clinical characteristics, remain poorly understood. In the Canary Islands, limpets (a type of marine gastropod) are widely consumed as part of the traditional cuisine. Despite isolated reports of limpet allergy, no large-scale studies or comprehensive clinical analyses have been published on this topic. A cohort of patients sensitized to limpets was analyzed: 66 patients were monosensitized to limpets (Group A), while 64 patients demonstrated additional sensitization to other shellfish (Group B). Limpet ingestion was associated with delayed and severe symptoms, including anaphylaxis and severe asthma. Notably, only 11.5% of patients in Group A tested positive for shellfish allergens using ALEX testing compared to 67.9% in Group B. The identification of protein bands in the 25–40 and 50–200 kDa molecular weight ranges in monosensitized patients provides a novel finding that differentiates this study from prior research. Our study represents the largest reported series of patients with documented limpet allergy to date.