Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 14 1 2015 02 15 19 27 EN Hilde Gundersen Department of Global Public Health and Primary Care, University of Bergen, Norway. Anette Harris Department of Health Promotion and Development, Faculty of Psychology, University of Bergen, Norway. Magne Bråtveit Department of Global Public Health and Primary Care, University of Bergen, Norway. Bente E Moen Department of Global Public Health and Primary Care, University of Bergen, Norway. 2015 10 16 The aetiology behind odor-related chronic somatic symptoms (O-RCSS) is unknown, although both immunological and psychiatric causes have been suggested. The aim of this study was to investigate the occurrence of self-reported asthma and hay fever and psychiatric symptoms in individuals having O-RCSS compared to individuals with similar chronic somatic symptoms (CSS) which were not odors-related, and also compared to healthy controls. Data from the Hordaland Health Study were used. 13,799 individuals, 40-45 years, answered a questionnaire including 16 questions related to somatic symptoms. They also indicated if the symptoms were odor-related, and answered questions about asthma and hay fever. Anxiety and depression were measured with the Hospital Anxiety and Depression Scale. 38 (0.6%) men and 106 (1.4%) women had O-RCSS, whereas 88 (1.5%) men and 192 (2.5%) women had CSS. Adjusted logistic regression analyses showed increased odds of self-reported asthma in those with O-RCSS compared to those with CSS (males: 3.81, 1.06-13.8, females: 2.60, 1.05-6.93) and compared to male and female controls (3.56, 1.89-6.68 and 4.81, 1.92-12.1 respectively). Increased odds of self-reported hay fever were in addition seen in females with O-RCSS. There were no differences in psychiatric symptoms between individuals with O-RCSS and CSS, although individuals in both groups showed increased odds compared to male and female controls. Increased occurrence of self-reported asthma was exclusively found among male and females with O-RCSS, compared to CSS and controls. Increased occurrence of psychiatric symptoms was seen both in individuals with O-RCSS and CSS. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/416 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/416/421