Revealing the Complexity of Allergies in Spain: A Multicenter Study on Sensitization Patterns and Clinical Implications

BACKGROUND AND OBJECTIVES: Defining a patient´s allergic profile by identifying the allergens that cause symptoms is essential for the design of specific, tailored immunotherapy, ensuring greater effectiveness in cases of polyallergy. Objective: This observational, multicenter study aimed to demonstrate the heterogeneity of the Spanish population with respiratory allergy by analyzing specific immunoglobulin E (sIgE) patterns for aeroallergens and exploring the relationship between sensitization and clinical symptoms. PATIENTS AND METHODS: A total of 474 patients with respiratory allergy from different regions of Spain were recruited based on their case histories and skin prick test data for aeroallergens. Serum samples were analyzed using ImmunoCAPTM assays to determine sIgE levels for 33 allergenic sources and 43 molecular allergens. RESULTS: Ninety percent of patients were polysensitized. Pollen was the most common cause of sensitization, followed by mites. Interestingly, polysensitization was significantly associated with the severity of rhinitis symptoms. The molecular diagnosis revealed Phl p 1 as the most prevalent pollen sensitizer. Sensitization to mites was mainly driven by Der p 2. Fel d 1 and Alt a 1 were the most frequently recognized allergens among patients sensitized to animal epithelia and molds, respectively. Moreover, sensitization to mite and animal epithelia allergens was significantly associated with more severe asthma symptoms. CONCLUSIONS: Our findings show a high prevalence of polysensitization and highlight the importance of molecular diagnosis for improving diagnostic accuracy and designing immunotherapy tailored to patients in the region.