ORIGINAL Atopy and sensitization to Tetranychus urticae

Background: The purpose of this study was to assess whether the use of different definitions of atopy (as found in the literature) might alter this condition's significance as a risk factor for sensitization to Tetranychus urticae in a popula-tion of greenhouse workers. Methods: The study population comprised 241 greenhouse workers, who were divided into two groups according to the presence (n = 61) or absence (n = 180) of T. urticae hypersensitivity. Clinical information was collected by means of a questionnaire, and skin prick tests were performed with a panel of airborne allergens com-mon in our environment. The distributions of clinical symptoms and of the results of the skin prick tests were compa-red between both groups. Results: No significant differences between the two groups existed when atopy was defined as the presence of clinical symptoms suggestive of an allergic condition. However, when the criterion for atopy was the presence of positive skin prick tests to common aeroallergens together with suggestive clinical manifestations, "atopy" became significantly more frequent among the workers in the group with T. urticae sensitization. Conclusions: The use of different definitions of atopy can affect its significance as a risk factor for sensitization to occupational allergens in epidemiological studies