The role of seasonal grass pollen on childhood asthma emergency department presentations
Article first published online: 20 APR 2012
© 2012 Blackwell Publishing Ltd
Clinical & Experimental Allergy
Special Issue: Special Issue on Severe Asthma
Volume 42, Issue 5, pages 799–805, May 2012
How to Cite
Cite this as: B. Erbas, M. Akram, S. C. Dharmage, R. Tham, M. Dennekamp, Clinical & Experimental Allergy, 2012 (42) 799–805.
- Issue published online: 20 APR 2012
- Article first published online: 20 APR 2012
- Accepted manuscript online: 8 MAR 2012 02:48PM EST
- Manuscript Accepted: 1 FEB 2012
- Manuscript Received: 1 NOV 2011
- Manuscript Revised: 1 NOV 2011
- environmental asthma;
- grass pollen
Few studies have focused on the role of grass pollen on asthma emergency department (ED) presentations among children. None have examined whether a dose-response effect exists between grass pollen levels and these asthma exacerbations.
To examine the association between increasing ambient levels of grass pollen and asthma ED presentations in children. To determine whether these associations are seen only after a thunderstorm, or whether grass pollen levels have a consistent influence on childhood asthma ED visits during the season.
A short time series ecological study was conducted for asthma presentations to ED among children in Melbourne, Victoria, and grass pollen, meteorological and air quality measurements recorded during the selected 2003 period. A semi-parametric Poisson regression model was used to examine dose-response associations between daily grass pollen levels and mean daily ED attendance for asthma.
A smoothed plot suggested a dose-response association. As ambient grass pollen increased to about 19 grains/m3, the same day risk of childhood ED presentations also increased linearly (P < 0.001). Grass pollen levels were also associated with an increased risk in asthma ED presentations on the following day (lag 1, P < 0.001).
This is the first study to establish a clear relationship between increased risk of childhood asthma ED attendance and levels of ambient grass pollen below 20 grains/m3, independent of any impact of thunderstorm-associated asthma. These findings have important implications for patient care, such as asthma management programs that notify the general public regarding periods of high grass pollen exposure, as well as defining the timing of initiation of pollen immunotherapy.