Baker's asthma: still among the most frequent occupational respiratory disorders.

BACKGROUND

Baker's asthma and rhinitis are among the most frequent occupational respiratory disorders.

OBJECTIVE

The aim of the study was to evaluate the frequency of work-related symptoms and the clinical relevance of sensitization to allergens in screened and symptomatic bakers.

METHODS

Eighty-nine bakers participating in a screening study and 104 bakers filing a claim for compensation were examined with regard to occupational and clinical case history, lung function parameters, and sensitization to bakery allergens by skin prick tests, specific IgE analyses, and inhalative challenge tests.

RESULTS

A high prevalence of respiratory disorders, abnormal lung function parameters, and sensitization to bakery allergens exists. Most frequently, bakers with workplace-related respiratory symptoms showed sensitization to wheat flour (64%), rye flour (52%), soy bean flour (25%), and alpha-amylase (21%). The correlation between these sensitizations and asthma case history and inhalative challenge test responses was significant. However, approximately 29% of the bakers with respiratory symptoms showed no sensitization to these bakery allergens, whereas 32% of the sensitized bakers in the screening group had no workplace-related symptoms. Atopic status defined by skin prick test sensitization to common allergens or elevated total IgE levels was found to be a risk factor for the development of sensitization to bakery allergens and respiratory symptoms. On the other hand, there is evidence for an increased frequency of elevated total IgE as the result of occupational allergen exposure because respective findings were observed in bakers without symptoms.

CONCLUSION

Sensitization to bakery allergens seems to be the main cause of baker's asthma and rhinitis but cannot explain the asthma case history in each case. Further methods are required to objectively assume irritative pathomechanisms. Our findings indicate the necessity for an improved primary prevention of exposure to inhalative noxae in bakeries.