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Summary: Hymenoptera venom allergy (HVA) is the most frequent cause of anaphylaxis in Europe, accounting for most of the severe reactions occurring in adults, and being the second cause of anaphylaxis in children. Prevention of further episodes in patients who developed a systemic reaction (SR) is based on the correct management of the allergic emergency, the referral to an allergist for a correct diagnosis, prescription of adrenaline auto-injectors (AAI) and specific venom immunotherapy (VIT), if recommended. Diagnosis is based on the classification of the type of reaction, confirmation of an IgE-mediated pathogenesis and the identification of the offending insect. The use of component resolved diagnostics may be helpful in case of poly-sensitization or negative allergy tests with a proven history of previous SRs. When a severe SR occurs, baseline serum tryptase levels should always be assessed. The prescription of AAI is recommended or suggested for untreated patients, patients undergoing VIT and after discontinuation of treatment, according to multiple evidence. VIT is the most effective treatment available for HVA patients, as confirmed by recent European guidelines. VIT has an early, sustained and persistent protective effect and modifies the natural course of the disease. Moreover, VIT proved to be safe and well tolerated. According to a recent systematic review, no treatment-related fatalities were recorded to date. Compared to AAI, VIT significantly improves the quality of life of HVA patients by reducing the anxiety and limitations in daily activities caused by the fear of stinging insects. The memory of a life-threatening experience is the most likely reason why adherence to VIT is higher compared to immunotherapy with inhalant allergens. Several risk factors in HVA have been identified that can influence not only the severity of sting reactions in untreated patents, but also the occurrence of side effects, treatment effectiveness and the risk of relapse after discontinuation of VIT. Patient and treatment-related risk factors must be considered while selecting the best candidates for VIT, the type and duration of treatment. In this paper we address the most important issues related to HVA and VIT that may have an impact on daily clinical practice.

An anaphylactic reaction due to a Hymenoptera sting is a clinical emergency, and patients, their caregivers as well as all healthcare professionals should be familiar with its recognition and acute management. This consensus report has been prepared by a European expert panel of the EAACI Interest Group of Insect Venom Hypersensitivity. It is targeted at allergists, clinical immunologists, internal medicine specialists, pediatricians, general practitioners, emergency department doctors, and any other healthcare professional involved. The aim was to report the scientific evidence on self-medication of anaphylactic reactions due to Hymenoptera stings, to inform healthcare staff about appropriate patient self-management of sting reactions, to propose indications for the prescription of an adrenaline auto-injector (AAI), and to discuss other forms of medication. First-line treatment for Hymenoptera sting anaphylaxis is intramuscular adrenaline. Prescription of AAIs is mandatory in the case of venom-allergic patients who suffer from mast cell diseases or with an elevated baseline serum tryptase level and in untreated patients with a history of a systemic reaction involving at least two different organ systems. AAI prescription should also be considered in other specific situations before, during, and after stopping venom immunotherapy., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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., (© 2011 John Wiley & Sons A/S.)

This paper examines the main features of the deliberate sting challenge with regard to the type of insect, the advantages and disadvantages of its use in untreated and treated patients and after discontinuation of specific immunotherapy.

Clinical indications for allergen immunotherapy ( AIT) in respiratory and Hymenoptera venom allergy are well established; however, clinical contraindications to AIT are not always well documented. There are some discrepancies when classifying clinical contraindications for different forms of AIT as 'absolute' or 'relative'. EAACI Task Force on 'Contraindications to AIT' was created to evaluate and review current literature on clinical contraindications, and to update recommendations for both sublingual and subcutaneous AIT for respiratory and venom immunotherapy. An extensive review of the literature was performed on the use of AIT in asthma, autoimmune disorders, malignant neoplasias, cardiovascular diseases, acquired immunodeficiencies and other chronic diseases (including mental disorders), in patients treated with β-blockers, ACE inhibitors or monoamine oxidase inhibitors, in children under 5 years of age, during pregnancy and in patients with poor compliance. Each topic was addressed by the following three questions: (1) Are there any negative effects of AIT on this concomitant condition/disease? (2) Are more frequent or more severe AIT-related side-effects expected? and (3) Is AIT expected to be less efficacious? The evidence, for the evaluation of these clinical conditions as contraindications, was limited, and most of the conclusions were based on case reports. Based on an extended literature research, recommendations for each medical condition assessed are provided. The final decision on the administration of AIT should be based on individual evaluation of any medical condition and a risk/benefit assessment for each patient. [ABSTRACT FROM AUTHOR]

Hymenoptera stings can cause severe systemic allergic reactions and occasionally fatal anaphylaxis, which contribute significantly to morbidity and deterioration in health-related quality of life. The latest epidemiological data confirm the importance of insect sting allergy as a cause of anaphylaxis. Despite the high prevalence of asymptomatic sensitization, the prevalence of sting-induced systemic reactions (SRs) is low. However, to date, no parameter has been identified that can predict who will have a future reaction and whether it will be a large local reaction or anaphylactic. The combination of several concomitant factors, which include environmental, genetics and individual factors, may account for the occurrence of a system reaction in individual patients. Several not completely known factors may be associated with the severity of systemic re-stings. As about 50% of subjects with fatal sting reactions had no documented history of a previous SR, greater insight of the natural history and risk factors is required, especially in asymptomatic sensitized subjects. For patients with SRs, prevention of future severe allergic reactions starts with referral to an emergency department, correct administration of epinephrine by medical staff, referral to an allergist and coaching for the self-administration of epinephrine. However, most insect sting victims failed to seek medical advice and hospital attendance does not always correlate with the severity of the allergic reaction. Moreover, only about one-third of patients received a prescription for self-injectable epinephrine and were officially referred to an allergist after being discharged, causing the non- or delayed prescription of specific immunotherapy. Significantly, this means that at least half of the sting fatalities in patients with a positive history could have been avoided through the timely administration of specific immunotherapy. These findings indicate the urgent need to educate the general population and doctors on the management of venom-allergic patients. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine whether a short interval (< 2 months) between two consecutive stings influences the development of Hymenoptera venom allergy. The study compared the sting-interval distribution in 120 allergic patients who experienced a first-time systemic reaction to a Hymenoptera sting, and in 100 healthy controls. A significant difference in sting-interval distribution between the two groups was found (P = 0.0001). In 71 of 120 allergic patients, the sting that provoked the systemic reaction had been preceded by another, completely tolerated sting not more than 2 months before. However, in the control group only four subjects out of 100 had received two consecutive stings within less than 2 months. In conclusion, a short interval between two consecutive stings seems to be a risk factor for the onset of Hymenoptera venom allergy. [ABSTRACT FROM AUTHOR]