Correlation of pollen counts and number of hospital visits of asthmatic and allergic rhinitis patients.

AIMS AND OBJECTIVES: Environmental pollens are known to cause exacerbation of symptoms of patients with allergic rhinitis (AR) and asthma. During pollen months, number of patients visiting hospital has been shown to increase in some studies. However, in India, such studies are lacking. Therefore, we aimed to study pollen counts and to find its correlation with number of new patients attending Asthma Bhawan for 2 years.

MATERIALS AND METHODS: Aerobiological sampling was done using Burkard 24 h spore trap system. The site selected for the entrapment of the air spore was the building of Asthma Bhawan situated at Vidhyadhar Nagar, Jaipur. New patients coming with problems of respiratory allergy such as AR or asthma were recruited in the study. Skin prick tests (SPTs) were carried out after obtaining consent in these patients. Monthly pollen counts of trees, weeds and grasses were correlated with the number of new patients. Pollen calendar was prepared for 2 years.

RESULTS: Average annual pollen count during 2011 and 2012 were 14,460.5. In the analysis, 37 types of species or families were identified. Pollen count showed two seasonal peaks during March-April and from August to October. January and June showed the lowest pollen counts in 2 years. Average monthly count of grass pollens showed significant correlation with number of new patients (r = 0.59). However, monthly pollen count of trees and weeds did not correlate. The correlation of the pollen count of individual pollen with the SPT positivity to that pollen showed significant correlation with Chenopodium album only.

CONCLUSIONS: It can be concluded that there were two peaks of pollen count in a year during March-April and August-October. Average monthly pollen counts of grass were significantly correlated with the number of hospital visits of new patients.