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Background There is controversy whether taking β‐blockers or ACE inhibitors (ACEI) is a risk factor for more severe systemic insect sting reactions (SSR) and whether it increases the number or severity of adverse events (AE) during venom immunotherapy (VIT). Methods In this open, prospective, observational, multicenter trial, we recruited patients with a history of a SSR and indication for VIT. The primary objective of this study was to evaluate whether patients taking β‐blockers or ACEI show more systemic AE during VIT compared to patients without such treatment. Results In total, 1,425 patients were enrolled and VIT was performed in 1,342 patients. Of all patients included, 388 (27.2%) took antihypertensive (AHT) drugs (10.4% took β‐blockers, 11.9% ACEI, 5.0% β‐blockers and ACEI). Only 5.6% of patients under AHT treatment experienced systemic AE during VIT as compared with 7.4% of patients without these drugs (OR: 0.74, 95% CI: 0.43–1.22, p = 0.25). The severity of the initial sting reaction was not affected by the intake of β‐blockers or ACEI (OR: 1.14, 95% CI: 0.89–1.46, p = 0.29). In total, 210 (17.7%) patients were re‐stung during VIT and 191 (91.0%) tolerated the sting without systemic symptoms. Of the 19 patients with VIT treatment failure, 4 took β‐blockers, none an ACEI. Conclusions This trial provides robust evidence that taking β‐blockers or ACEI does neither increase the frequency of systemic AE during VIT nor aggravate SSR. Moreover, results suggest that these drugs do not impair effectiveness of VIT. (Funded by Medical University of Graz, Austria; Clinicaltrials.gov number, NCT04269629).

BackgroundHypersensitivity reactions to anaesthetic agents are rare but often severe, with a mortality ranging from 4 to 9% in IgE-mediated events. Identification of the risk factors may contribute to limit the incidence of these reactions. The aim of our study was to search for possible risk factors of severe perioperative hypersensitivity reactions in our study population.MethodsFor this study we retrospectively reviewed data from 193 patients who experienced drug hypersensitivity reactions during general anaesthesia. The diagnostic protocol consisted of 1) history of the reaction, 2) measurement of serum baseline tryptase and specific IgE-assays for latex, beta-lactams and succinylcholine, 3) skin tests for the agents listed in the anaesthesia chart and for others likely to be safe for future use, latex, and others medications administered during the perioperative period (i.e. antibiotics), 4) subdivision of our patients on the basis of two criteria: a) grade of severity of clinical reactions according to the Ring and Messmer classification; b) results of skin tests and/or serum specific IgE-assays.ResultsOne hundred of 193 patients had reactions of grade I, 32/193 patients had reactions of grade II, 55/193 patients had reactions of grade III and 6/193 patients had reactions of grade IV. A diagnosis of IgE-mediated reaction was established in 55 cases (28.50%); the most common causes were neuromuscular blocking agents, followed by latex and beta-lactams. Severe reactions were associated with older age (p = 0.025), asthma (p = 0.042), history of hypertension (p = 0.001), intake of serum angiotensin converting enzyme inhibitor medication (p = 0.012) or serum angiotensin II antagonist (p = 0.033), higher levels of basal tryptase (p = 0.0211). Cardiovascular symptoms (p = 0.006) and history of hypersensitivity to antibiotics (p = 0.029) were more frequently reported in IgE-mediated reactions.ConclusionsWe confirmed the relevance of several clinical features as risk factors for anaphylactic reactions induced by anaesthetic agents: older age, asthma, hypertension and antihypertensive drugs. We observed increased levels of serum basal tryptase in severe reactions: this finding may signify that this biomarker is useful for the identification of patients at risk.Electronic supplementary materialThe online version of this article (doi:10.1186/s12948-015-0017-9) contains supplementary material, which is available to authorized users.

ObjectiveTo assess the relationship between serum tryptase and the occurrence of major cardiovascular and cerebrovascular events (MACCE) at 2-year follow-up in patients admitted with acute coronary syndrome (ACS). To compare serum tryptase to other validated prognostic markers (maximum high-sensitivity troponin (hs-Tn), C reactive protein (CRP) levels at admission, Synergy between percutaneous coronary intervention with Taxus and Cardiac Surgery (SYNTAX) score).MethodsWe measured serum tryptase at admission in 140 consecutive patients with ACS and in 50 healthy controls. The patients’ follow-up was maintained for 2 years after discharge. The predictive accuracy of serum tryptase for 2-year MACCE was assessed and compared with hs-Tn, CRP and SYNTAX score.ResultsSerum tryptase levels at admission were significantly higher in patients with ACS compared with the control group (p=0.0351). 2 years after discharge, 28/140 patients (20%) experienced MACCE. Serum tryptase levels, maximum hs-Tn measurements and SYNTAX score were higher in patients who experienced MACCE compared with those without (p<0.0001). Conversely, we found no significant association between MACCE and CRP. The predictive accuracy of serum tryptase for MACCE was set at the cut-off point of 6.7 ng/mL (sensitivity 46%, specificity 84%).ConclusionsIn patients with ACS, serum tryptase measured during index admission is significantly correlated to the development of MACCE up to 2 years, demonstrating a possible long-term prognostic role of this biomarker.

Background: β-Lactam antibiotics (mainly amoxicillin, AX) are the drugs that most frequently induce systemic drug allergy reactions. Objective: We attempted to identify the risk factors associated with systemic reactions to AX. Methods: All patients who were referred to our department for suspected hypersensitivity reactions to AX over a 6-month period were evaluated for anti-AX immunoglobulin E (IgE) levels and skin-test positivity for β-lactams. Age, sex, concomitant diseases, therapies, total IgE, serum tryptase levels and signs and symptoms suggesting mast cell activation syndrome (MCAS) were analyzed in relation to the severity of the reaction in accordance with the Mueller classification. Results: Sixty-seven patients were selected: 39 with mild reactions such as cutaneous or gastrointestinal symptoms (grades I and II) and 28 with severe systemic reactions (grades III and IV). Anti-AX IgE levels and total IgE were significantly higher in severe reactions than in mild ones (p < 0.00005, p = 0.0037). Treatment with histamine-2 receptor antagonists (anti-H2) was significantly related to severe reactions (p = 0.007). No significant correlations were found between the severity of the reactions and dyslipidemia or levels of angiotensin-converting enzyme and tryptase. Conclusion: Anti-AX IgE levels were the most significant immunological parameter distinguishing patients who presented with severe reactions to AX and those with mild reactions. Higher values of total IgE, the use of gastroprotective drugs and signs and symptoms suggesting an MCAS significantly increased the odds ratio of having a severe reaction. The risk of serious adverse reactions to AX increased in older patients and in males, but this trend was not significant.