Pollen Food Allergy Syndrome in Southern European Adults: Patterns and Insights

Oral Allergy Syndrome (OAS) is an allergic reaction that occurs upon contact of the mouth and throat with food, leading to symptoms primarily affecting the oral mucosa. In patients with allergic rhinitis, OAS may develop due to cross-reactivity between the pollen allergens responsible for allergic rhinitis, and specific plant-derived foods. This particular type of OAS is known as Pollen Food Allergy Syndrome (PFAS). The difference in prevalence of PFAS across different regions of the world is attributed to various factors, including environmental exposure and dietary habits. Southern Europe’s temperate climate favors the blooming of many allergenic plants, making respiratory allergies and PFAS significant public health concerns. There is a regional variation in pollen in Southern Europe, contributing to differences in the presence of panallergens—such as profilins, pathogenesis-related class 10 (PR-10) proteins and lipid transfer proteins (LTPs)—which mediate PFAS. In order to examine the epidemiology, pathogenesis, and diagnostic approaches of OAS and PFAS, focusing on their prevalence and impact in Southern European adults, a narrative review was performed. Data from Portugal, Spain, France, Italy, Albania, Greece, and Türkiye were retrieved. The main outcome of this review was that the frequency of PFAS varies across studies, not only between countries but also within the same country, due to vegetation variability across regions as well as methodological differences and the year of study. However, despite these differences, PFAS emerges as a common issue in Southern Europe, underscoring the need for effective diagnosis and management.