Prevalence of occupational allergy to Chrysanthemum pollen in greenhouses in the Netherlands

Background: An increasing number of allergic complaints appear to have occurred among Chrysanthemum greenhouse employees. The aim of this study was to estimate the prevalence of work‐related allergic symptoms and the prevalence of sensitization to pollen of different members of the Chrysanthemum family. Methods: We studied 104 employees who were invited to answer an extensive questionnaire and to complete a rhinitis quality of life questionnaire. In addition, they were skin prick tested on location with inhalant allergens and home‐made pollen extracts of seven different members of the Chrysanthemum family. Radio‐allergo‐sorbent tests were performed to confirm IgE‐mediated reactions. Results: Work‐related symptoms were reported in 56.7% of all cases, with the main symptom being rhinitis. Sensitization to Chrysanthemum pollen was found in 20.2% of the employees without one member of the Chrysanthemum family in particular being most prevalent. Sensitization to Chrysanthemum pollen was considered to be an important risk factor for the occurrence of work‐related symptoms of the upper airways. Furthermore, inhalant atopy as well as sensitization to common airborne pollen including mugwort were closely associated with sensitization to Chrysanthemum what might be suggestive for cross‐sensitization. Conclusions: There is a high prevalence of work‐related symptoms in Chrysanthemum greenhouses. In one‐third of the employees these symptoms were caused by an IgE‐mediated allergy caused by the pollen of the flowers. Inhalant atopy appeared to have a great impact on the development of such a sensitization. Measurements to reduce the pollen exposure are necessary to prevent a further increase of this occupational allergy.