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 mm3 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.