@article {GuarnieriP3481, author = {Gabriella Guarnieri and Patrizia Bonadonna and Michele Schiappoli and Piero Maestrelli}, title = {Unexpected severe systemic allergic reaction after hymenoptera sting in well controlled asthma during treatment with omalizumab}, volume = {44}, number = {Suppl 58}, elocation-id = {P3481}, year = {2014}, publisher = {European Respiratory Society}, abstract = {Omalizumab has been used as add-on therapy for patients at high risk of anaphylaxis during specific venom immunotherapy (1). We reported the case of a 64-year-old man, suffering from severe allergic asthma since 1986. In February 2008 he started treatment with Omalizumab (300 mg twice per month), added to high doses of inhaled corticosteroids and long-acting bronchodilators and montelukast. Omalizumabwaswell tolerated. Respiratory symptoms, lung function and quality of life improved. He remained stable until August 2012, when he experienced a severe systemic allergic reaction after a wasp sting (grade III according Mueller classification). The intradermal skin tests and the specific IgE level were positive to all hymenoptera venom. CAP-inhibition assays showed that Vespula was the main venom responsible for the adverse reaction. Tryptase level was normal (9 μg/l). Venom immunotherapy for Vespula was started according to a rush modified regimen, continuing with Omalizumab therapy. Maintenance dose was reached in 7 weeks and well tolered. The mechanism for which severe systemic allergic reaction to hymenoptera venom occurred despite concomitant anti-IgE therapy remains unknown. It may be assumed that the dose of Omalizumab used for asthma treatment was not sufficient to prevent reactions to hymenoptera venom or was given at excessive interval from the wasp sting (2 weeks before). Another explanation could be that the systemic reaction was elicited by a non IgE-mediated release of mediators.1. Galera C et al. J Investig Allergol Clin Immunol 2009; 19(3):225-9.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/44/Suppl_58/P3481}, eprint = {https://erj.ersjournals.com/content}, journal = {European Respiratory Journal} }