Search

To better understand atmospheric pollen transport and to define the allergic risks incurred by an individual throughout the day, airborne pollen was counted continuously for several weeks, using a Cour pollen trap inside and outside a house in Saint-Priest, a town east of Lyon, France. The results of this preliminary study revealed a large variety of pollen inside the house. Approximately 60% of the taxa found in the environment close to the house were also present inside the house during the same period. Ragweed pollen, which is responsible for severe seasonal allergy, was the most prevalent taxon. These results underline the importance of pollen grains accumulating inside a house. It therefore seems advisable to investigate the factors responsible for the variations observed in the proportion of pollen grains transported into the interior of a house and to estimate the potential impact on pollen-allergic patients. [Copyright &y& Elsevier]

We used data obtained in the Lyon-Bron region from 1982 to 2001 with the Cour pollen trap, a particularly sensitive measuring device, to study the main parameters that are used to forecast the onset of pollination of common ragweed. This predictive model had been defined in 1989 and the results have been published in the media since 1994. Analysis of the data showed that the onset of pollination was advancing over the past 20 years. The advance of the date of pollination is significant, registering an average of 11 days (range 6 to 16 days), with an advance of as much as a month in some years, depending on the criteria used. The regression line provides a forecast for 2002. We discuss the possibility that pollen counts taken over a long period might be used to measure climatic warming? From the point of view of the allergist, the wide year-to-year variations observed should be taken into account in the treatment of patients with ragweed allergy, confirming the potentially useful aspect of the predictive model produced by the AFEDA. These results indicate that there is every interest in continuing to determine pollen counts annually and to make the results public in real time, which could lead to an improvement in the care of the allergic patient. The regression line of the annual pollen counts is an additional factor to be considered, and it should be updated each year. [Copyright &y& Elsevier]

This study was focused on the pollination periods of nine taxons of trees during the period 1985 to 2000 in the Lyon-Bron region using Cour pollen traps. Trees studied were: cypress, alder, poplar, ash, birch, plane tree, oak, pine and chestnut. For each type of tree, we noted the dates for the beginning, the peak and the end of pollination. An increasingly earlier onset of pollination was observed during the period studied. [Copyright &y& Elsevier]

Cypress belongs to the Cupressaceae family, which includes 140 species with non-deciduous foliage. The most important genera in allergic diseases are Cupressus sempervirens or Green cypress, Cupressus arizonica or Blue cypress, Juniperus oxycedrus, Juniperus communis and Thuya. Because J. oxycedrus pollinates in October, C. sempervirens in January and February, C. arizonica in February and March, J. communis in April, the symptomatic period is long-lasting. Because of global warming, the pollination period is tending to last longer and Cupressaceae species are becoming established further the north. In Mediterranean countries, cypress is by far the most important pollinating species, accounting for half of the total pollination. The major allergens belong to group 1. The other allergens from cypress and Juniper share 75 to 97 % structural homology with group 1 major allergens. The prevalence of cypress allergy in the general population ranges from 5 % to 13 %, according to exposure to the pollen. Among outpatients consulting an allergist, between 9 and 35 %, according to different studies, are sensitized to cypress pollen. Repeated cross-sectional studies performed at different time intervals have demonstrated a threefold increase in the percentage of cypress allergy. Risk factors include a genetic predisposition and/or a strong exposure to pollen, but air pollutants could play a synergistic role. The study of the natural history of cypress allergy allows the identification of a subgroup of patients who have no personal or family history of atopy, whose disease began later in life, with low total IgE and often monosensitization to cypress pollen. In these patients, the disease is allergic than rather atopic. In the clinical picture, rhinitis is the most prevalent symptom but conjunctivitis the most disabling. A cross-reactivity between cypress and peach allergy has been demonstrated. The pharmacological treatment of cypress allergy is not different from that for other allergies. Hyposensitization has been used, at first by injection, but nowadays mostly through the sublingual route, but clinical trials have included few patients. Avoidance can be implemented at the individual level but also at the community levels using alternative plants, low-pollinating cypresses or by trimming hedges prior to pollination., (Copyright © 2013. Published by Elsevier Masson SAS.)

Today the Cupressaceae are seen as one of the most allergenic plant families in the mediterranean region. A comparative study of Cupressaceae pollen concentration as sampled in Lyon-Bron (temperate region) and in Montpellier (mediterranean region) has been conducted. During the last 20 years, this family of plant has increasingly been represented in the pollinic spectra. In Montpellier the annual mean pollen concentration went from 43 pollen grains m3 of air at the beginning of the eighties to 72 pollen grains at the beginning of the years 2000. In Lyon, the progression is above 200% but with lesser annual mean pollen concentrations: 4.5 pollen grains m3 of air at the beginning of the eighties to 13.7 pollen grains at the beginning of the years 2000. The annual mean pollen concentration in the Lyon region still modest compared to the mediterranean stations, shows a steep increase though, that should be taken care of.