Search

Background: Large local reactions to insect stings cause significant morbidity and impair quality of life. Venom immunotherapy is not recommended because of a low risk for future systemic reaction and unproven efficacy in preventing large local reactions. Objective: To determine the feasibility of performing a controlled trial to examine the efficacy of venom immunotherapy in reducing the size and duration of large local reactions. Methods: Sting challenge in 41 patients with previous large local reactions and positive venom skin tests caused large local reactions 16 cm or larger in 34 patients, and 29 consented to treatment. Venom immunotherapy was initiated in 19, and 10 were untreated controls. Sting challenge was repeated after 7 to 11 weeks (control patients then began venom immunotherapy), and annually for as long as 4 years. Results: After 7 to 11 weeks of treatment, the size and duration of large local reactions decreased 42% and 53%, respectively, in treated patients and 18% in controls (P < .01 for both). The response was similar after 1 year, and improved after 2 to 4 years to 60% and 70%, respectively. Conclusions: Venom immunotherapy significantly reduced the size and duration of the large local reactions, and the efficacy improved over a period of 2 to 4 years of treatment. Further studies are needed to establish the safety and efficacy of venom immunotherapy for large local reactions, the optimal duration of treatment, and the mechanism for the differences in degree and rate of clinical response compared with venom immunotherapy in systemic reactors. [Copyright &y& Elsevier]

Background: The reported frequency of systemic reactions to challenge sting varies greatly. Objective: To evaluate the interaction of clinical and entomological factors that determine the outcome of a challenge sting. Methods: Patients allergic to yellow jacket were stung and monitored for systemic reaction. The frequency and severity of sting reactions were analyzed in relation to the species of insect used and patient characteristics. Results: Objective systemic reactions occurred in 21 of 69 patients (30%) stung with Vespula maculifrons and in 8 of 71 patients (11%) with Vespula germanica (P = .005). Systemic reactions were more frequent in patients with a severe history (9/30; 30%) than in those with a mild or moderate history (21/145; 14%; P = .04). In only 1 of 111 patients (0.9%) was the reaction to sting challenge more severe than previous reactions. The reaction rate was higher when venom skin tests were positive at <1.0 μg/mL (17/75 = 23%) than when sensitivity was milder (9/100 = 9%; P = .012). We compared sting outcome and venom-induced histamine release in relation to insects collected in July or in October, and found no difference. Conclusion: Allergic reactions to sting challenge are determined by the species of yellow jacket used, the severity of previous sting reactions, and the degree of skin test sensitivity, but not by the time of year. These factors are important to clinicians when they evaluate the chance of reaction to a future sting and to researchers when they design and report sting challenge studies. [Copyright &y& Elsevier]

Background: Venom allergen immunotherapy (VIT) is proven to be highly effective for insect allergy, but the mechanisms and the biomarkers associated with clinical efficacy remain elusive. Objective: The aim of this study was to identify candidate biomarkers associated with successful VIT. Methods: Gene chip array and clustering analyses of PBMCs from subjects with or without VIT were performed. Results: From gene chip array and clustering analyses, an increased expression of osteopontin was found in patients who completed 5 to 6 years of VIT and discontinued therapy for 3 to 6 years (completed treatment group) compared with the untreated group. A significantly higher level of serum osteopontin was found in the completed treatment group compared with the untreated group (n=16 in each group; P < .001). Conclusion: The upregulation of osteopontin after VIT suggests a role of osteopontin as a candidate biomarker for VIT. [Copyright &y& Elsevier]

Whole-body extracts of Hymenoptera were used for diagnosis and treatment until controlled clinical trials proved them no better than placebo, whereas venom is 85% to 98% effective. Studies of natural history reveal why whole-body extracts were thought to work. The chance of future systemic reactions is low in large local reactors and in most children and varies between 20% and 70% in adults. Venom skin tests are most accurate, but RAST is an important complementary test. The degree of sensitivity on skin tests or RASTs does not reliably predict the severity of a sting reaction. Venom immunotherapy is recommended for patients at high risk for sting reactions. Rapid regimens are as safe as slower regimens. The recommended dose is 100 μg, but some patients require higher doses for full protection. Venom immunotherapy is continued every 4 to 8 weeks for at least 5 years in most cases. Skin test results become negative in only 25% after 5 years of therapy but in 60% to 70% after 7 to 10 years. When treatment is stopped after 5 years or more, there is a 10% chance of systemic reaction to each future sting, but most reactions are mild. Some patients have a higher risk of relapse and should continue treatment for an extended period. [ABSTRACT FROM AUTHOR]

These parameters were developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma and Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing “Stinging insect hypersensitivity: a practice parameter update II.” Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or the ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma and Immunology. This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. These parameters are not designed for use by pharmaceutical companies in drug promotion. The Joint Task Force understands that the cost of diagnostic tests and therapeutic agents is an important concern that may appropriately influence the work-up and treatment chosen for a given patient. The Joint Task Force recognizes that the emphasis of our primary recommendations regarding a medication may vary, for example, depending on third party payer issues and product patent expiration dates. However, since a given test or agent''s cost is so widely variable, and there is a paucity of pharmacoeconomic data, the Joint Task Force generally does not consider cost when formulating Practice Parameter recommendations. In extraordinary circumstances, when the cost benefit of an intervention is prohibitive as supported by pharmacoeconomic data, commentary may be provided. [Copyright &y& Elsevier]