Airborne exposure-induced occupational type I allergy to Tenebrio molitor: Case report and studies on immunological reactivity

This occupational case report describes a 28-year-old woman, employed since November 2020 as a research assistant working with mealworms (<i>Tenebrio molitor</i>), who developed symptoms of mild shortness of breath and severe redness and swelling of the eyes in early 2022, leading to the diagnosis of occupational allergic asthma due to respiratory sensitization to mealworm. Subsequent tests confirmed mono-sensitization to <i>T. molitor</i> and additional cross-sensitization to flour beetle (<i>Tribolium confusum</i>). Further studies aimed to determine the antigenic and allergenic potency of different protein fractions and rearing material isolated from <i>T. molitor</i> regarding protein pattern and immunological activity by <i>T. molitor</i>-specific polyclonal rabbit IgG and human IgE. The highest antigen content of <i>T. molitor</i> was measured in the rearing material, followed by mealworm flour and aqueous extraction. Allergenic proteins are particularly detected in mealworm flour and aqueous fraction at molecular weights of 24 and 11 kDa, which appear to be specific for primary airway sensitization. In addition, the airborne <i>T. molitor</i> antigen levels in the workplace were monitored using electrostatic dust collectors to identify hotspots of exposure. The disposal of dry insect material was shown to be responsible for the unintentional release of potential allergens. Therefore, awareness of the potential risk of a type I allergy due to the release of airborne insect allergens in the workplace should be raised.