What proportion of rhinitis symptoms is attributable to atopy?

The aim of this study was to assess what proportion of patients with rhinitis symptoms (unrelated to infection) in population-based studies is attributable to atopy. We assessed the relevance of atopy in rhinitis in different countries and populations and between different age groups by performing a Medline search from 1980 onward on population-based studies. In the 22 identified population-based studies found, the overall proportion of rhinitis cases that were atopic was 61%, the proportion of noncases that were atopic was 20%, and the proportion of rhinitis cases that were attributable to atopy was 53%. There is variation between studies but little evidence of systematic geographic variation. For future research on the prevalence and possible increase of atopic rhinitis, it seems to be of major importance to differentiate between atopic and other forms of rhinitis.