PURPOSE OF THE STUDY.
To assess the association between pollen count and severe seasonal allergic rhinitis (SAR) after controlling for air pollution levels and other confounders.
A nationwide sample of 36 397 patients in France who were suffering from SAR as defined by Symptomatic Global Score in the upper third quartile and were consulting a physician (general practitioner, ear-nose-throat specialist, pediatrician, or allergist) between May and August 2004. Patients were untreated and had uncomplicated SAR. Patients from all age groups were included.
A multilevel model relating severity of SAR as the dependent variable and pollen counts and air pollution levels as independent variables was used. To understand the respective roles of pollen counts and air pollutants, 2 models were used: (1) a model taking into account only daily airborne pollen counts and (2) a model with both daily pollen counts and air pollution concentration.
A rise of 60 grass pollen grains per cubic meter increased the risk of severe SAR by 8% after adjusting for confounders (age, gender, address) and air pollution levels.
Grass pollen count aggravated SAR in terms of nasal and ocular symptoms in the nationwide sample, and the relationship between severity of SAR and grass pollen counts was not modulated by air pollution.
This is a large study that quantifies the magnitude of change in SAR severity in relation to measured grass pollen counts. Because air pollution levels did not significantly modify this relationship, monitoring of pollen counts can be informative for the management of SAR regardless of the air quality.
- Copyright © 2013 by the American Academy of Pediatrics