Allergic rhinitis phenotypes based on mono-allergy or poly-allergy.

Background: Allergic rhinitis (AR) is characterized by typical symptoms that are dependent on inflammation. Poly-allergy is a frequent phenomenon. Phenotyping AR represents an up-to-date issue. Objective: The aim of this study was to evaluate whether the number of allergies is able to define different phenotypes in patients with AR. Methods: 83 patients (43 males, mean age 34.7 years) suffering from AR were evaluated. Sensitization, VAS for nasal symptoms perception, and nasal cytology were evaluated. Results: Poly-allergic patients perceived more severe nasal obstruction than mono-allergic ones (p = 0.0006) as well as they had more frequent sneezing (p < 0.0001). Moreover, poly-allergic patients had a more intense inflammatory infiltrate, concerning both eosinophils (p = 0.0005) and mast cells (p = 0.0001), than mono-allergic patients. Conclusions: The present study demonstrates that the presence of poly-allergy could define a distinct AR phenotype in comparison with mono-allergy. It could be clinically relevant as poly-allergic patients have more intense inflammation and more severe symptoms than mono-allergic ones.