[Meteorologic conditions leading to crisis situations in allergic patients]

The prime cause of allergy attacks lies in the presence in the air of agents causing violent reactions in susceptible subjects. The origin of these agents (allergens) is generally vegetable (pollens, spores) or domestic (dusts) in nature. The author considers the meteorological conditions favouring the formation of pollens, spores and dusts. He shows the fundamental differences in the formation and accumulation of irritants present in industrial or domestic smoke (notably smog). In common with irritants, allergens are not only found near their place of production, but are often carried very long distances. The author cites a number of examples of appreciable distances frequently covered, given favourable meteorological conditions. He concludes that it is nevertheless possible for an individual to prevent allergy attacks through careful choice of his place of residence and by taking the likelihood of the transport of allergens (season, predominant winds, etc.) into account.