Seasonal asthma may be associated with pollen exposure, but the pollens responsible for these exacerbations are not well known. The association between ambient pollen and asthma reflected in emergency department (ED) visits and hospitalizations, although studied intensively, has shown inconsistent results. This would be explained by differences between population, climate, and measurement of pollen.We can talk about maple, charm, oak pollen and grasses, with in the Darrow's study a 3% increase in emergency department visits. Another study shows that birch and oak pollen peaks were associated with antiallergic treatment sales and ED visits for asthma attacks.Similarly, relationship between pollen peaks and allergic rhinitis, rhinosinusitis, conjunctivitis has been highlighted in the literature reviews, with a close link connecting these peaks to the consumption of antiallergic treatment (oral and local), including a study on Clermont Ferrand with grass pollen, ash, hazel and birch.However, it is interesting to note that ED visits for asthma are in the case of severe exacerbation and do not represent the majority of asthma attacks.