Background: The aim of the study was to evaluate the prevalence, incidence and risk factors of hypersensitivity to alpha-amylase as well as to identify allergy-related clinical symptoms in apprentice bakers.
Materials and methods: A group of 287 apprentice bakers was examined by using a questionnaire, performing skin prick tests to common and occupational allergens, and evaluating total serum IgE level, specific anti-flour and alpha-amylase IgE before, 1 year and 2 years after the onset of vocational training. To diagnose occupational respiratory disease, spirometry, histamine and allergen specific inhalation challenge tests were performed.
Results: None of the apprentices displayed the presence of alpha-amylase-specific IgE before starting vocational training. After the first year of occupational exposure, one subject developed hypersensitivity to alpha-amylase, and other 27 subjects after the second year. Generally, 28 (9.8%) apprentices showed hypersensitivity to alpha-amylase after two years of occupational exposure. Of those subjects, 17 (60.7%) had occupational allergic rhinitis recognized and 15 (53.6%) occupational asthma. Logistic regression analysis revealed that the positive results of SPT to common allergens and moulds are significant risk factor for the development of hypersensitivity to alpha-amylase (OR = 11.98, 95% CI: 2.60-55.08 and OR = 7.45, 95% CI: 1.12-49.61, respectively).
Conclusion: The incidence of allergy to alpha-amylase increases with increasing duration of exposure. Hypersensitivity to common allergens, especially to moulds, is a risk factor of occupational allergy to alpha-amylase. The study results confirm that skin prick tests to common allergens, particularly to moulds, should be performed in bakers before starting occupational exposure and subjects with positive results should be considered as a group of high risk of occupational allergy.