Exposition aux pollens et consommation de médicaments antiallergiques

The aim of the present study was to analyze the short-term relationship between pollen exposure and antiallergic drug consumption in the general population, taking into account confounding factors such as atmospheric pollution and meteorological parameters. Data on the daily consumption of antiallergic drug by individuals in the Clermont-Ferrand urban area from January 1 2000 through December 31 2001 and from January 1 2002 through December 31 2003, was obtained from the French health insurance database. An episode of allergic rhinoconjunctivitis (ARC) was defined as the association of an oral antihistamine and a local-acting antiallergic drug on the same prescription. The relationship between daily changes in atmospheric pollen concentration and daily changes in the number of treated ARC cases was analyzed using time series analysis. The results showed that the risk of treated ARC increased significantly with an interquartile increase in pollen concentration for grasses (5%, P < 0.001), hazel (7%, P < 0.02), birch (7%, P < 0.001) and ash (2%, P < 0.001). The effect was significant on the same day for all except the grasses, for which the risk lasted three days. Time series studies of antiallergic drug consumption may be useful for assessing the risk of exposure to pollens in an ambulatory population.