Prevalence and risk factors for self-reported odour intolerance: the Skövde population-based study

Objectives: The present study was performed to determine the prevalence of odour intolerance in adults with respect to both self-reported general intolerance and affective and behavioural consequences. Furthermore, we aimed to relate odour intolerance to explanatory variables and risk factors. Method: This is a cross-sectional, population-based epidemiological study. A random sample of 1900 inhabitants from the age of 20, stratified for age and gender, were recruited. Subjects were invited for clinical examinations that included questions about general odour intolerance, respiratory symptoms and smoking habits, as well as a smell identification test. The chemical sensitivity scale for sensory hyperreactivity (CSS-SHR) was used to quantify affective and behavioural consequences. Results: In total 1387 volunteers (73% of the sample) were investigated. The overall prevalence of self-reported general odour intolerance was 33% (95% confidence interval (CI): 30–36%), with problems mainly from the upper respiratory tract. The prevalence of affective and behavioural consequences of odour intolerance (CSS-SHR score ≥43) was 19% (95% CI: 15–22%). The risk for the latter condition was increased in women compared with men (odds ratio = 2.3: 95% CI: 1.5–3.6), but no increased risk was found related to current smoking or impaired sense of smell. Conclusion: This study demonstrates that intolerance to odours is a widespread problem in society, and that it is about twice as common in women than in men.