Ipersensibilità al veleno degli imenotteri. Aggiornamento delle Linee Guida della società Italiana di allergologia e immunologia clinica

Allergic reactions to hymenoptera stings concern about 3% of the general population and are caused by antigens occurring in venom, such phospholipase, hyaluronidase and, for vespids, antigen 5. Diagnosis is based on skin tests and in vitro tests, while the challenge with live insect is not recommended. Cross-reactivity of IgE antibodies to some allergens or to carbohydrate epitopes may result in apparent polysensitization and in difficulties in venom choice for immunotherapy. Another useful in vitro data, especially in patients with severe reactions, is measurement of tryptase, that may reveal an unrecognized mastocytosis. Management of hymenoptera venom allergy is based on pharmacological treatment of anaphylactic reactions, that absolutely requires epinephrine by intramuscular injection (also by auto-injectors for self-administration), and on prevention of further reactions. This is optimally achieved by venom immunotherapy (VIT), which demonstrated the complete capacity to prevent fatal reactions and to prevent more than 90% of reactions of any type, though with a lower efficacy if honeybee venom is used. VIT can be safely stopped after 5 years in most patients, but the occurrence of adverse reactions to treatment, of incomplete protection to stings, or of a concomitant mastocytosis indicates the need to continue VIT even life-span. Increasing the interval between venom administration up to 16 weeks favours the long-term compliance. This document updates the recent advances in diagnosis and treatment of hymenoptera venom allergy and discuss the possible future development