The seasonal variation in allergic rhinitis and its correlation with outdoor allergens in Kuwait

Background: Allergic rhinitis (AR) is the most common allergic problem in Kuwait. Most of the patients who have either AR or asthma are referred to the Al-Rashed Allergy Center. Objective: To determine if there is a seasonal variation in AR in Kuwait and to correlate it with the daily pollen count. Methods: Information about the new patients referred to the center over a 5-year study period (1996-2000) was extracted from the center's records. The daily pollen count in Kuwait city was obtained from the Air Biology Laboratory. Results: There was a significant seasonal variation with a bimodal increase in the number of patients with AR referred to the center. The main peak in the number of patients occurred in September October, and there was a smaller peak in April-May. The mean number +/-SD of new patients per month over the 5-year period varied from 87 +/- 32 for December to 367 +/- 104 for September. Similarly, the average daily pollen count varied from 3.7 +/- 1.0 pollens per mm(3) in January to 124 +/- 92 in October. There was high correlation between the number of new AR patients and the average total pollen count (Pearson correlation, r = 0.77, p ! 0.001), as well as with Chenopodiaceae and Amaranthaceae (weed) pollens (r = 0.75, p < 0.001), while there was no correlation between the number of new patients and either tree or grass pollens. Conclusion: Seasonal AR occurs during two periods in Kuwait, i.e. September October and April-May, with September-October being the main season. The rise in AR during late summer in Kuwait is mainly associated with the pollination of Chenopodiaceae species. Copyright (C) 2004 S. Karger AG, Basel.