Legumes in bread baking: A hidden risk for an IgE-mediated inhalant allergy.

New protein-rich flour blends from legumes are increasingly being processed for gluten-free bakery products, which may increase the risk of IgE-mediated sensitization through inhalation exposure. In the described case of a 29-year-old baker, work incapacity occurred due to respiratory complaints following exposure to various gluten-free baking ingredients. Occupation-related sensitization to "chestnut pea flour" (flour from lightly roasted and ground yellow peas) was identified, while the patient showed no IgE sensitization to five other ingredients. Significant allergic respiratory reactions occurred during bronchial challenge test with "chestnut pea" extract. Based on the test results and typical workplace-related symptoms, recognition of occupational disease was recommended. Further identification of potential causal allergens using IgE blot and allergen component-resolved diagnostics revealed IgE bindings to typical storage proteins, 2S albumin and vicilin, as well as to Bet v 1 homologous of "chestnut pea" and non-specific lipid transfer proteins. This case illustrates that the processing of protein-rich legume flours can pose new sensitization risks for workers, which should be considered in the future.