Background: Although recent reports show a worldwide increase in allergic diseases during the past 10-20 years, few epidemiological studies on secular trend and the age-specific prevalence of allergic rhinitis have been carried out in Japan. We conducted a study to clarify the age-specific prevalence of allergic rhinitis and cedar pollinosis to provide baseline data for a prospective study and to investigate the association of rhinitis with both environmental and personal factors among 2,307 Japanese men.
Methods: Allergic rhinitis was determined from self-reported allergic rhinitis or from the seasonal symptoms of the nose. Seasonal rhinitis was defined as symptoms evoked in the subjects from February to May. Cedar pollinosis was defined as the presence of cedar-specific IgE positivity among subjects with seasonal rhinitis.
Results: The prevalences of allergic rhinitis, seasonal rhinitis, and cedar pollinosis were 35.5, 28.8, and 11.0%, respectively. Age was a negative risk factor for all allergic conditions. Allergic family history and residence along a main street were strong risk factors for all allergic rhinitis.
Conclusions: The current prevalence of each rhinitis was higher than previously reported. The risk factors were similar for each allergic rhinitis except for a past history of atopy.