Epidemiology of rhinitis in Thais: characteristics and risk factors.

A questionnaire survey was performed on 3,124 subjects living in Bangkok and its vicinity. The cumulative prevalence of chronic rhinitis (CR) was 13.15% (95% CI = 13.13-13.17). The characteristics of CR subjects, i.e. age group, current occupation, associated allergy, family history of atopy, cigarette smoking and drinking habits were totally different from the non CR group, except for sex preponderance. The possible risk factors for developing CR in this group were high income occupation, presence of associated allergy, family history of atopy, smoking and drinking habits. When CR subjects were further classified into "allergic" and "non-allergic" CR groups by using the presence of associated eye symptoms and known provoking factors as the differential criteria, there was no significant difference in all parameters compared between the two groups, i.e. age, sex, current occupation, associated allergy, family history of atopy, smoking and drinking habits, frequency of occurrence of each nasal symptom, seasonal variation of the symptoms, effect of moving to live in the big city, presence of pets in the house and effect of changing occupation, except for the number of nasal symptoms which was significantly higher in the "allergic" CR group.