House dust allergens of children with newly diagnosed hazelnut or sesame allergy.

Background: Hazelnut and sesame are among the leading causes of immunoglobulin E mediated food allergies in the eastern Mediterranean region. Notably, initial allergic reactions often occur on the first known oral exposure, which suggests a potential role of non-oral routes of sensitization, including environmental exposure. Objectives: The study aimed to investigate the presence of environmental hazelnut and sesame allergens. Methods: House dust samples were collected from the homes of children newly diagnosed, previously diagnosed, and nonallergic (control) with or without hazelnut or sesame allergy. Results: A total of 57 and 63 house dust samples were analyzed for hazelnut and sesame allergens, respectively. In the hazelnut allergy group, newly diagnosed patients had a significantly higher rate of detectable hazelnut antigen (53%) compared with both previously diagnosed (20%) and control (15%) groups (p < 0.001 for both comparisons). Moreover, the amount of hazelnut antigen was higher in the newly diagnosed group compared with controls (median [interquartile range {IQR}] 0.1 µg/mL [0-0.8 µg/mL] versus 0.0 µg/mL [0-0 µg/mL]; p < 0.001). For sesame allergy, the previously diagnosed group had lower rates of detectable antigen (55%) compared with the newly diagnosed (74%) and control (100%) groups (p < 0.001 for both). In addition, the quantity of sesame antigen was higher in the control group compared with the previously diagnosed group (median [IQR] 1.41 µg/mL [0-1.085 µg/mL] versus 0.39 µg/mL [0.882-3.645 µg/mL]; p < 0.001). Notably, within the control homes, sesame antigen was detected more frequently (100% versus 15%) and in greater amounts (median [IQR] 1.21 µg/mL [0.88-3.64 µg/mL] versus 0.0 µg/mL [0-0 µg/mL]) versus hazelnut antigen. Conclusion: The detection of hazelnut and sesame allergens in household dust, particularly at higher rates and quantities in the environments of patients with newly diagnosed allergy, supports the potential role of environmental exposure in the development of these food allergies. Further studies are needed to clarify the timing, dose, and clinical relevance of such exposures in sensitization pathways.