Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 10 3 2011 09 15 183 188 EN Giorgio Ciprandi Department of Internal Medicine, Azienda Ospedaliera Universitaria San Martino, Genoa, Italy Mara De Amici Pediatric Clinic- University of Pavia-Foundation IRCCS San Matteo, Pavia, Italy Mariangela Tosca Pneumology and Allergy Unit, Istituto Giannina Gaslini, Genoa, Italy Roberta Alesina Pneumology, Foundation IRCCS San Matteo, Pavia, Italy Gianluigi Marseglia Pediatric Clinic- University of Pavia-Foundation IRCCS San Matteo, Pavia, Italy Dietmar Fuchs Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria 2015 10 01 Allergic rhinitis (AR) is a very frequent disease which is not only characterized by nasal symptoms, but also with behavioural changes. This study evaluated the serum serotonin levels in patients with pollen-induced AR during and outside the pollen season. One-hundred-two  (56 females, 46 males, median age: 28.7 years) were included in this study: 56 with seasonal AR (SAR) evaluated outside the pollen season and so without allergic inflammation and symptoms, and 46 with SAR evaluated during the pollen season with symptoms. Blood specimens were collected to assess serum concentrations of serotonin and to compare results to scores of a Quality of Life (QoL) questionnaire which was performed in all subjects. Serotonin serum concentrations were higher in AR patients out of pollen season than in (p<0.01). There was a very strong direct relationship between QoL and serotonin concentrations. This preliminary study demonstrates that SAR influences serotonin concentrations and that serum serotonin could serve as a biomarker in AR patients with behavioural symptoms. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/309 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/309/309