Objectives: The aim of the study was to assess the predictive value of known risk factors of asthma, such as atopy, exposure to pet allergens at home, and tobacco smoking, in predicting the occurrence of occupational respiratory allergy due to high-molecular-weight allergens.
Methods: A questionnaire study, skin-prick tests (SPTs) for common and occupational allergens, and evaluation of total and - in selected cases - specific IgE, were performed in 357 apprentice bakers before and after a year of vocational training.
Results: Mean age of examined subjects was 17.2+/-0.5 years. The prevalence of newly developed symptoms was 7% for rhinitis, 3.1% for chest symptoms, and 3.6% for skin symptoms. The frequency of at least one positive SPT result changed from 17.9% to 24.4% after the 1st year of vocational training, including SPTs for common allergens - from 16.8% to 22.7%, and for occupational allergens - from 2% to 8%. The proportion of subjects with elevated total IgE level increased from 38.7% to 44.3%. Generally, after a year of vocational training 9.2% of examined subjects presented hypersensitivity to occupational allergens. Logistic regression analysis revealed that positive results of SPTs for common allergens (odds ratio (OR) =4.4; 95% confidence intervals (CI) 1.9, 10.27) and elevated IgE level (OR=3.6; 95%CI 1.55, 8.57) were significant risk factors of hypersensitivity to occupational allergens.
Conclusions: In apprentice bakers hypersensitivity to occupational allergens develops even during vocational training. SPTs for common allergens, performed before apprentices started their vocational training, would enable the identification of subjects at the highest risk of sensitisation to occupational allergens.