Mastocytosis or an elevated basal serum tryptase (bST) level are known risk factors for patients with insect venom allergy. We report on 3 patients with a history of severe anaphylactic insect sting reactions who underwent a detailed workup for insect venom allergy before starting venom immunotherapy. In addition to insect venom sensitization, an elevated concentration of bST (15.5, 20.8, and 23.2 µg/L) was found in all cases. There was no evidence of mastocytosis in the skin (MIS). Further testing revealed hereditary α-hypertryptasemia (HαT) in 2 patients and a D816V mutation by liquid biopsy in 1 patient, which is a minor diagnostic criterion for indolent systemic mastocytosis. Even without iliac crest puncture, causes of elevated bST can be narrowed down with minimally invasive diagnostic measures. As this has practical implications, patients with elevated bST should always undergo further work-up to determine the cause of this abnormal finding.

Before starting venom-specific immunotherapy (VIT), systemic sting reactions to Hymenoptera venoms require allergological workup in order to prove an IgE-mediated reaction and to identify the culprit insect venom. In addition to skin tests and the determination of specific IgE antibodies, the basophil activation test (BAT) using flow cytometry has emerged as a powerful tool and sensitive marker for this purpose in recent years. BAT seems to have a better informative value in terms of clinical relevance compared to the other tests. In Hymenoptera venom allergies, BAT is particularly useful for the diagnosis of cases with unclear or contradictory history and sensitization profile. Its results are associated with adverse reactions during VIT and efficacy of VIT and therefore have a certain predictive value for side effects and treatment failure of VIT. In research, it is mainly used to characterize the allergenic components of Hymenoptera venoms. This review article focuses on these topics.

Understanding the risk factors leading to severe systemic sting reactions (SSR) is crucial for initiating venom immunotherapy (VIT) and for educating affected individuals and their families. Some of these risk factors are well-established, some are no longer considered risk factors, and some remain controversial. Well-established risk factors for severe SSR include clonal mast cell disease, high baseline serum tryptase, and advanced age. The absence of skin symptoms and the rapid onset of symptoms are indicators of severe SSR. Recent publications indicate that antihypertensive treatment and stings in the head and neck area are not risk factors for severe SSR. VIT is the only available treatment that can potentially prevent further anaphylactic reactions. Although rare and generally manageable, individuals undergoing VIT may experience systemic adverse events (sAE). More sAE are expected in patients undergoing bee VIT compared to vespid VIT. The role of elevated baseline serum tryptase as a risk factor for sAE remains debated, but if it is a factor, the risk is increased by only about 1.5-fold. Rapid up-dosing protocols, depending on the specific regimen, can also be associated with more sAE. Severe initial SSR, antihypertensive medication, high skin test reactivity, and high specific IgE levels are not risk factors for sAE.

UNASSIGNED: Background. In diagnosing insect venom allergy and making immunotherapy decisions, clinical history, skin tests, and specific serum IgE levels are commonly utilized. This study aims to emphasize the clinical significance of using the basophil activation test in accurately identifying sensitivities in individuals with insect venom allergy and to compare its effectiveness with other testing methods. Methods. This study included a total of 43 patients, who experienced at least one systemic allergic reaction following insect stings and were deemed suitable for immunotherapy.Basophil activation test, specific serum IgE levels, and skin prick test results utilized in making immunotherapy treatment decisions were recorded. Results. Our study determined that the overall clinical sensitivities of the basophil activation test (BAT), specific serum IgE (spIgE), and skin prick test (SPT) for apis mellifera were 95.5%, 95.7%, and 48.4% respectively, while for vespula vulgaris, they were 83.3%, 100%, and 33.3%. Based on these results, the prediction of systemic reactions to bee stings is ordered as spIgE > BAT > SPT. Additionally, early-stage skin prick tests showed a sensitivity of 67% and specificity of 50% at a cut-off value of 1.5 mm, and 33% sensitivity and 83% specificity at 2.5 mm. Conclusions. This study demonstrates that the basophil activation test (BAT) can provide a high positive predictive value in immunotherapy treatment decisions and offer significant insights in clinical practices.

Stinging ants represent a wide range of over 200 different species across the world, of which Solenopsis, Myrmecia, Pogonomyrmex, and Brachyponera genera account for a substantial economic and healthcare burden. S. invicta (red imported fire ant [IFA]) and M. pilosula (jack jumper ant [JJA]) are 2 species of high clinical importance, known to cause anaphylaxis in humans, with numerous reported fatalities. Diagnostic testing should be performed in patients with a history of a systemic reaction with skin testing and/or in vitro specific immunoglobulin E (IgE) testing. In vitro testing is commercially available for IFA through whole-body extract specific IgE and JJA venom-specific IgE, but not widely available for other stinging ant species. Commercial venom component testing for IFA and JJA is currently not available. Patients with a clinical history and positive specific IgE testing should undergo treatment with specific immunotherapy, which is currently available for IFA and JJA. Buildup may be performed using conventional, semi-rush, rush, or ultra-rush schedules with similar risk profiles for IFA. Optimal duration for whole=body extract immunotherapy for IFA and specific JJA venom immunotherapy is not well studied, but generally recommended for at least 3 to 5 years. Sting challenges are used in research settings, primarily to assess treatment efficacy of immunotherapy.

Insect stings can cause large local reactions (LLRs) that are IgE-mediated and associated with considerable morbidity. A risk for systemic reactions including anaphylaxis to subsequent stings has been reported and is often noted by patients and health care providers. Guidelines do not recommend venom immunotherapy (VIT) for LLRs based on the relatively low risk of anaphylaxis, but this is debated in this review. On the pro side: the risk of anaphylaxis may be higher than reported in the limited literature, especially in patients who had only 1 LLR; new species with more potent stings are spreading into new areas; the quality of life can be markedly impaired by LLRs; and VIT is generally safe and highly effective. On the con side: LLRs are benign, stings occur infrequently, VIT has significant cost, systemic reactions occur more often to VIT than to stings in patients with LLRs, and Food and Drug Administration approval and published guidelines do not recommend VIT for LLRs. In practice, shared decision-making is appropriate to incorporate knowledge of the natural history and known high-risk factors in the context of the patient\'s personal values and preferences.

This review summarizes new research developments and clinical practice recommendations for the diagnosis and management of anaphylaxis presented in the Joint Task Force on Practice Parameters 2023 Anaphylaxis practice parameter Update. It is intended to serve as a high-level summary of the 2023 practice parameter, which makes clinically impactful recommendations based on evidence that has emerged since the 2015 practice parameter. We invite clinicians to explore the full 2023 practice parameter to understand the research methods and underlying evidence that have informed the recommendations summarized here. There are new and evolving diagnostic criteria for anaphylaxis, rules for defining elevated tryptase levels, and recognition of signs and symptoms particular to infants and toddlers. The administration of epinephrine should not be used as a surrogate to diagnose anaphylaxis. Risk factors for anaphylaxis should be assessed on a case-by-case basis. Patient counseling and shared decision-making are essential to support patients\' treatment decisions and capacity to manage the risk of anaphylaxis at home and in other community settings. Activation of emergency medical services after home epinephrine administration may not be required in all cases, and patients should be engaged in shared decision-making to determine when home management may be appropriate.

Background: Allergen immunotherapy (AIT) is a well-established and efficient method of causative treatment for allergic rhinitis, asthma and insect venom allergy. Traditionally, a recent history of malignant neoplasm is regarded as a contraindication to AIT due to concerns that AIT might stimulate tumor growth. However, there are no data confirming that the silencing of the Th2 response affects prognosis in cancer. Objectives: The aim of this study was to investigate frequency of malignant tumors in patients undergoing AIT and the association between AIT and cancer-related mortality. Patients and Methods: A group of 2577 patients with insect venom allergy undergoing AIT in 10 Polish allergology centers was screened in the Polish National Cancer Registry. Data on cancer type, diagnosis time and patients\' survival were collected and compared with the general population. Results: In the study group, 86 cases of malignancies were found in 85 patients (3.3% of the group). The most common were breast (19 cases), lung (9 cases), skin (8 cases), colon and prostate cancers (5 cases each). There were 21 cases diagnosed before AIT, 38 during and 27 after completing AIT. Laplace\'s crude incidence rate was 159.5/100,000/year (general population rate: 260/100,000/year). During follow-up, 13 deaths related to cancer were revealed (15% of patients with cancer). Laplace\'s cancer mortality rate was 37.3/100,000/year (general population rate: 136.8/100,000/year). Conclusions: Malignancy was found in patients undergoing immunotherapy less often than in the general population. Patients with cancer diagnosed during or after AIT did not show a lower survival rate, which suggests that AIT does not affect the prognosis.

Evaluation and management of insect sting allergy are often not straightforward when there is uncertainty about the history of reaction, the significance of test results, and the risk of severe reaction to future stings. Patients encounter misinformation about the chance of reaction and may have strong beliefs about the need for treatment. Shared decision-making encourages the clinician to listen to the patients\' concerns and beliefs, share relevant information and evidence, and partner with patients to incorporate their values and preferences. This review discusses some major decision points in diagnosis and treatment of insect-allergic patients, with attention to the potential burdens or harms that are important to patients and factors that relate to patients\' values and preferences concerning the choices they must make. This is especially true in patients with no history of moderate to severe sting anaphylaxis in whom the risk may be overestimated, but it can also be important in patients who underestimate the risk associated with severe sting anaphylaxis. Clinicians should become more knowledgeable about patient-important beliefs and outcomes and engage in shared decision-making to help patients understand and be comfortable with the choices they must make.

Stinging insects are a frequent cause of local and systemic hypersensitivity reactions, including anaphylaxis. For those with a history of life-threatening anaphylaxis, venom immunotherapy is effective, safe, and can be life-saving. Arachnids are a much less common source of envenomation through bites or stings and are less likely to cause a hypersensitivity reaction. However, recognizing the clinical manifestations when they do present is important for accurate diagnosis and treatment, and, when indicated, consideration of other diagnoses.