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.

Nasal endoscopic findings in patients with perennial allergic rhinitis.

Nasal endoscopy was carried out in 83 patients with perennial allergic rhinitis to evaluate endonasal anatomic variation and to find the correlation between the symptoms of patients and the endoscopic findings. All of the patients had nasal symptoms, 7.2% of the patients were runner, 7.2% were blocker and 85.6% were both. 86.75% of the patients had allergy-related symptoms, i.e. throat symptoms (73.5%), sinus headache (50.6%), and smell disturbance (10.8%). 95.2% of patients had abnormal endoscopic findings, i.e. deviated nasal septum (72.3%), abnormal middle turbinate (49.4%), narrowing of the entrance into the frontal recess (30.1%), septal spur (25.3%), obstruction of the entrance into the frontal recess (19.3%), nasal polyps (15.7%), mucopurulent discharge (14.5%), inferior turbinate hypertrophy (10.8%), abnormal uncinate process (9.6%), abnormal ethmoid bullae (7.2%), and enlargement of aggar nasi cells (2.4%). There was no significant correlation between each symptom and each endoscopic finding. However, there was a significant correlation between sinus headache and all of the combined abnormal endoscopic findings (P<0.05). These findings suggested that variations in endonasal anatomy was not by itself a pathology or a cause of symptoms. However, a combination of these variations may narrow the cleft of the ostiomeatal unit and cause contact area or stenosis, which predisposed patients to persistent symptoms, recurrent infection or resistance to therapy in patients with perennial allergic rhinitis. The endoscope might be a very useful tool for allergists, immunologists, and rhinologists, who work in the nose to deal with these cases.