title: Risk of sensitization and allergy in Ragweed workers - a pilot study.
abstract: BACKGROUND
  Due to its high allergenic potential Ambrosia artemisiifolia has become a health threat in many European countries during the last few decades. Hence, several cities and communities initiated ragweed eradication campaigns. In Berlin, Germany, so-called Ambrosia scouts are being assigned the task of finding and eliminating this weed. We sought to evaluate the potential risk of sensitization and allergy in these individuals.
  
  
  RESULTS
  In order to assess the risk of sensitization and allergy, we followed-up 20 Ambrosia scouts by skin-prick test with inhalant allergens, immunoserological and pulmonary function tests. Additionally, medical conditions were evaluated by a questionnaire especially designed for this study. Despite close contact to ragweed over a median duration of 13.8 months, none of the participants became sensitized or allergic to ragweed. One individual developed a clinical non-relevant sensitization towards the taxiconomically-related plant mugwort. A decline in relative FEV1 was most probably due to heavy smoking.
  
  
  CONCLUSIONS
  Our surprising findings suggest that intensive contact and exposure to high ragweed pollen concentrations do not necessarily result in sensitization and/or allergy, meaning that the allergenic potential of this weed might be lower than hitherto expected. However, it is also conceivable that continuous exposure to high allergen levels induced tolerance in the ragweed workers. Due to the relatively small number of subjects studied, our results might be biased and therefore investigations on larger study groups are needed.
authors.affiliation: Department of Dermatology and Allergy, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Brandt
authors.affiliation: Department of Dermatology and Allergy, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Zuberbier
authors.affiliation: Department of Dermatology and Allergy, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: Karl-Christian
authors.initials: KC
authors.lastname: Bergmann
keywords: Allergic asthma; Allergic rhinoconjunctivitis; Occupational risk; Pollen allergy; Ragweed; Sensitization