Anaphylaxis caused by Hymenoptera stings: from epidemiology to treatment.

Hymenoptera venom allergy occasionally causes fatal reactions. The prevalence of systemic reactions (SRs) is 0.3-8.9%, with anaphylaxis in 0.3-42.8% of cases. Factors contributing to reaction severity include older age, insect type, a previous less severe SR, preexisting diseases, concomitant treatments, mast cell diseases and elevated baseline tryptase serum concentration. Venom immunotherapy (VIT) is highly effective, as shown by sting challenge and spontaneous field stings. Indications for VIT are based on history of an SR, positive diagnostic tests, natural history and established risk factors for a severe outcome. Current strategies for reducing adverse reactions include anti-IgE monoclonal antibody pretreatment, and purified aqueous and purified aluminium hydroxide adsorbed preparations. New strategies for VIT, mostly using recombinant allergen, are in development. Further improvements will increase the safety and efficacy of VIT.