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P Demoly - One of the best experts on this subject based on the ideXlab platform.
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optimal step doses for drug provocation tests to prove beta lactam hypersensitivity
Allergy, 2017Co-Authors: A M Chiriac, P J Bousquet, Ticha Rerkpattanapipat, Nicolas Molinari, P DemolyAbstract:Background Drug provocation tests (DPT) are commonly performed as part of s-lactam allergy work-up, in case of Negative Skin tests, and in the absence of contraindications. The recommendations of learned societies have created a frame for DPT performance, but protocols vary widely between centres, generating various hypothesis-driven protocols (i.e., empirical dosing, driven by both safety concerns and practical aspects). Methods The primary objective of this retrospective analysis was to detect eliciting dose thresholds (reactive doses) during s-lactam DPT, using the survival analysis method, in order to suggest optimal step doses. Our secondary objective was to evaluate the safety of our 30-minute incremental one-day protocol. The study included all the patients explored in the Allergy Unit of the University Hospital of Montpellier (France), between September 1996 and July 2015 for a suspicion of drug hypersensitivity reaction to s-lactams, with Negative Skin tests and positive DPT. Results During the study period, 182 positive DPT (accounting for 171 hypersensitive patients) were analysed. We identified eliciting thresholds and we suggest the following steps for DPT to s-lactams: 5%-15%-30%-50% of daily therapeutic dose (with additional lower steps for index reactions of anaphylaxis). We confirm the safety of one-day protocol for immediate and mild non-immediate reactors, for both children and adults, with a surveillance period of 2h after the last administered dose, and a prolonged surveillance after discharge of 48 hours. Conclusion This data-driven approach in designing DPT protocols is a step forward in improving DPT standardization, starting with the most frequently tested drugs, s-lactam antibiotics. This article is protected by copyright. All rights reserved.
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clinical value of Negative Skin tests to iodinated contrast media
Clinical & Experimental Allergy, 2010Co-Authors: Silvia Caimmi, B Benyahia, D Suau, L Bousquetrouanet, D Caimmi, P J Bousquet, P DemolyAbstract:Background Several studies have shown that Skin tests are useful tools for the diagnosis of iodinated contrast medium (ICM) allergy, but the real number of false Negative results is not known. Objective To evaluate the Negative predictive value of ICM Skin tests. Material and Methods One hundred and fifty-nine patients tested in our department because of a previous ICM reaction over the last 9 years were called and asked standardized questions about ICM re-exposure. Results Twenty-nine patients had been re-exposed to ICM. There were 20 (69.0%) females and the median age was 55 (34–60) years. The median time interval between the reaction and Skin testing was 11.9 (1.6–21.5) years. Twenty-four patients (82%) had an immediate reaction, four a non-immediate (13.8%) reaction and no data were available for one patient. Two patients had positive ICM Skin tests previously and were re-exposed to a Negatively Skin-tested ICM and did not react. Only two patients presented a mild reaction during ICM re-injection: one immediate (generalized urticaria lasting for 3 days) and one non-immediate maculopapular reaction. The patient with urticaria was re-tested and re-challenged (Negative). The other patient was unable to return for re-testing. Conclusion Skin testing for ICM hypersensitivity has a Negative predictive value of 96.6% (95% CI: 89.9–103.2) and none of the reactions in Skin-test-Negative patients were severe. Multi-centric large surveys are still needed for confirmation. Cite this as: S. Caimmi, B. Benyahia, D. Suau, L. Bousquet-Rouanet, D. Caimmi, P.-J. Bousquet and P. Demoly, Clinical & Experimental Allergy, 2010 (40) 805–810.
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oral challenges are needed in the diagnosis of β lactam hypersensitivity
Clinical & Experimental Allergy, 2007Co-Authors: P J Bousquet, L Bousquetrouanet, A Pipet, P DemolyAbstract:Summary Background β-lactams continue to remain the most commonly involved drug family in allergic drug reactions. They are often essential and there is a cost-effective and favourable risk-benefit ratio for the exploration of all suspicions of β-lactam allergy. A firm diagnosis is always based on Skin tests and sometimes on provocation tests. Recommendations have been published by allergy societies and distinguished scientists but they are not always concordant and can lead to some confusion for the practicing allergologist. The situation has even worsened since the world wide withdrawal of these penicillin determinants and since the predominance of amoxicillin and cephalosporin prescriptions in most countries. Objective – Method In a recent article, it was stated that patients with a penicillin allergy history and Negative Skin tests to major and minor penicillin determinants are at a low risk of relapse (0–5%) when receiving a β-lactam. In this paper, our Drug Allergy and Hypersensitivity Database, a cohort database, was used to demonstrate that this statement is false. Standardized European Network for Drug Allergy questionnaires, Skin test and challenge procedures were followed. Results One-thousand two-hundred and eighteen subjects, 69.8% of female, 51.7% of atopics, were included. 21.1% had a true β-lactam allergy confirmed by Skin tests (178, 69.3%) or by drug provocation (79, 30.7%). 17.4% of the patients with Negative Skin tests to major and minor penicillin determinants were positive for a β-lactam. Conclusion In the diagnosis of β-lactams allergy, if all Skin tests are Negative, Skin tests with other determinants and provocation tests under strict surveillance are mandatory.
Suran L Fernando - One of the best experts on this subject based on the ideXlab platform.
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assessing cross reactivity to neuromuscular blocking agents by Skin and basophil activation tests in patients with neuromuscular blocking agent anaphylaxis
BJA: British Journal of Anaesthesia, 2019Co-Authors: Oliver Giles Best, Michael Rose, Sarah Green, Richard B Fulton, Marc J Capon, Benedict A Krupowicz, Suran L FernandoAbstract:Abstract Background Following diagnosis of neuromuscular blocking agent (NMBA) anaphylaxis, identifying safe alternatives for subsequent anaesthesia is critical. A patient with anaphylaxis to one NMBA can also have an allergic reaction to other NMBAs (cross-reactivity). Whilst drug provocation testing is standard for identifying or excluding allergy, there is significant risk. In vitro, after an allergen activates basophils, basophils express surface activation markers that can be measured by basophil activation testing (BAT). We compared cross-reactivity between NMBAs assessed by BAT against that by Skin testing. Methods All patients attending an anaesthetic allergy clinic in Sydney, Australia between May 2017 and July 2018 diagnosed with NMBA anaphylaxis qualified for this study comparing intradermal Skin tests and BAT with a panel of NMBAs (rocuronium, vecuronium, pancuronium, suxamethonium, cisatracurium). Results Of the 61 patients participating, sensitisation on Skin testing and on BAT completely matched in only nine patients (15%). Sensitisation was not in agreement for pancuronium, cisatracurium and rocuronium, but was in agreement for vecuronium and suxamethonium. Nine patients with Negative Skin tests subsequently tolerated cisatracurium, and one false positive on BAT to cisatracurium was detected. Conclusions The utility of BAT in identifying safe NMBAs for subsequent anaesthesia needs further evaluation. BAT detects a different cross-reactivity profile to Skin tests. Negative Skin testing and BAT might increase confidence in performing drug provocation testing, but this and follow-up of subsequent anaesthesia in our cohort is necessary to determine the clinical significance of BAT sensitisation.
P J Bousquet - One of the best experts on this subject based on the ideXlab platform.
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optimal step doses for drug provocation tests to prove beta lactam hypersensitivity
Allergy, 2017Co-Authors: A M Chiriac, P J Bousquet, Ticha Rerkpattanapipat, Nicolas Molinari, P DemolyAbstract:Background Drug provocation tests (DPT) are commonly performed as part of s-lactam allergy work-up, in case of Negative Skin tests, and in the absence of contraindications. The recommendations of learned societies have created a frame for DPT performance, but protocols vary widely between centres, generating various hypothesis-driven protocols (i.e., empirical dosing, driven by both safety concerns and practical aspects). Methods The primary objective of this retrospective analysis was to detect eliciting dose thresholds (reactive doses) during s-lactam DPT, using the survival analysis method, in order to suggest optimal step doses. Our secondary objective was to evaluate the safety of our 30-minute incremental one-day protocol. The study included all the patients explored in the Allergy Unit of the University Hospital of Montpellier (France), between September 1996 and July 2015 for a suspicion of drug hypersensitivity reaction to s-lactams, with Negative Skin tests and positive DPT. Results During the study period, 182 positive DPT (accounting for 171 hypersensitive patients) were analysed. We identified eliciting thresholds and we suggest the following steps for DPT to s-lactams: 5%-15%-30%-50% of daily therapeutic dose (with additional lower steps for index reactions of anaphylaxis). We confirm the safety of one-day protocol for immediate and mild non-immediate reactors, for both children and adults, with a surveillance period of 2h after the last administered dose, and a prolonged surveillance after discharge of 48 hours. Conclusion This data-driven approach in designing DPT protocols is a step forward in improving DPT standardization, starting with the most frequently tested drugs, s-lactam antibiotics. This article is protected by copyright. All rights reserved.
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clinical value of Negative Skin tests to iodinated contrast media
Clinical & Experimental Allergy, 2010Co-Authors: Silvia Caimmi, B Benyahia, D Suau, L Bousquetrouanet, D Caimmi, P J Bousquet, P DemolyAbstract:Background Several studies have shown that Skin tests are useful tools for the diagnosis of iodinated contrast medium (ICM) allergy, but the real number of false Negative results is not known. Objective To evaluate the Negative predictive value of ICM Skin tests. Material and Methods One hundred and fifty-nine patients tested in our department because of a previous ICM reaction over the last 9 years were called and asked standardized questions about ICM re-exposure. Results Twenty-nine patients had been re-exposed to ICM. There were 20 (69.0%) females and the median age was 55 (34–60) years. The median time interval between the reaction and Skin testing was 11.9 (1.6–21.5) years. Twenty-four patients (82%) had an immediate reaction, four a non-immediate (13.8%) reaction and no data were available for one patient. Two patients had positive ICM Skin tests previously and were re-exposed to a Negatively Skin-tested ICM and did not react. Only two patients presented a mild reaction during ICM re-injection: one immediate (generalized urticaria lasting for 3 days) and one non-immediate maculopapular reaction. The patient with urticaria was re-tested and re-challenged (Negative). The other patient was unable to return for re-testing. Conclusion Skin testing for ICM hypersensitivity has a Negative predictive value of 96.6% (95% CI: 89.9–103.2) and none of the reactions in Skin-test-Negative patients were severe. Multi-centric large surveys are still needed for confirmation. Cite this as: S. Caimmi, B. Benyahia, D. Suau, L. Bousquet-Rouanet, D. Caimmi, P.-J. Bousquet and P. Demoly, Clinical & Experimental Allergy, 2010 (40) 805–810.
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oral challenges are needed in the diagnosis of β lactam hypersensitivity
Clinical & Experimental Allergy, 2007Co-Authors: P J Bousquet, L Bousquetrouanet, A Pipet, P DemolyAbstract:Summary Background β-lactams continue to remain the most commonly involved drug family in allergic drug reactions. They are often essential and there is a cost-effective and favourable risk-benefit ratio for the exploration of all suspicions of β-lactam allergy. A firm diagnosis is always based on Skin tests and sometimes on provocation tests. Recommendations have been published by allergy societies and distinguished scientists but they are not always concordant and can lead to some confusion for the practicing allergologist. The situation has even worsened since the world wide withdrawal of these penicillin determinants and since the predominance of amoxicillin and cephalosporin prescriptions in most countries. Objective – Method In a recent article, it was stated that patients with a penicillin allergy history and Negative Skin tests to major and minor penicillin determinants are at a low risk of relapse (0–5%) when receiving a β-lactam. In this paper, our Drug Allergy and Hypersensitivity Database, a cohort database, was used to demonstrate that this statement is false. Standardized European Network for Drug Allergy questionnaires, Skin test and challenge procedures were followed. Results One-thousand two-hundred and eighteen subjects, 69.8% of female, 51.7% of atopics, were included. 21.1% had a true β-lactam allergy confirmed by Skin tests (178, 69.3%) or by drug provocation (79, 30.7%). 17.4% of the patients with Negative Skin tests to major and minor penicillin determinants were positive for a β-lactam. Conclusion In the diagnosis of β-lactams allergy, if all Skin tests are Negative, Skin tests with other determinants and provocation tests under strict surveillance are mandatory.
Silvia Caimmi - One of the best experts on this subject based on the ideXlab platform.
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clinical value of Negative Skin tests to iodinated contrast media
Clinical & Experimental Allergy, 2010Co-Authors: Silvia Caimmi, B Benyahia, D Suau, L Bousquetrouanet, D Caimmi, P J Bousquet, P DemolyAbstract:Background Several studies have shown that Skin tests are useful tools for the diagnosis of iodinated contrast medium (ICM) allergy, but the real number of false Negative results is not known. Objective To evaluate the Negative predictive value of ICM Skin tests. Material and Methods One hundred and fifty-nine patients tested in our department because of a previous ICM reaction over the last 9 years were called and asked standardized questions about ICM re-exposure. Results Twenty-nine patients had been re-exposed to ICM. There were 20 (69.0%) females and the median age was 55 (34–60) years. The median time interval between the reaction and Skin testing was 11.9 (1.6–21.5) years. Twenty-four patients (82%) had an immediate reaction, four a non-immediate (13.8%) reaction and no data were available for one patient. Two patients had positive ICM Skin tests previously and were re-exposed to a Negatively Skin-tested ICM and did not react. Only two patients presented a mild reaction during ICM re-injection: one immediate (generalized urticaria lasting for 3 days) and one non-immediate maculopapular reaction. The patient with urticaria was re-tested and re-challenged (Negative). The other patient was unable to return for re-testing. Conclusion Skin testing for ICM hypersensitivity has a Negative predictive value of 96.6% (95% CI: 89.9–103.2) and none of the reactions in Skin-test-Negative patients were severe. Multi-centric large surveys are still needed for confirmation. Cite this as: S. Caimmi, B. Benyahia, D. Suau, L. Bousquet-Rouanet, D. Caimmi, P.-J. Bousquet and P. Demoly, Clinical & Experimental Allergy, 2010 (40) 805–810.
R F Shen - One of the best experts on this subject based on the ideXlab platform.
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Physical and numerical modeling of drag load development on a model end-bearing pile
Geomechanics and Engineering, 2013Co-Authors: R F Shen, C F Leung, Yean Khow ChowAbstract:A centrifuge model study is carried out to investigate the behavior of pile subject to Negative Skin friction induced by pile installation, ground water drawdown and surcharge loading. A single end-bearing pile is examined as the induced Negative Skin friction would induce the most severe stress on the pile structural material as compared to friction piles. In addition, the behavior of the pile under simultaneous Negative Skin friction and dead/live loads is examined. To facilitate detailed interpretations of the test results, the model setup is extensively instrumented and involves elaborate test control schemes. To further examine the phenomenon of Negative Skin friction on an end-bearing pile, finite element analyses were conducted. The numerical analysis is first validated against the centrifuge test data and subsequently extended to examine the effects of pile slenderness ratio, surcharge intensity and pile-soil stiffness ratio on the degree of mobilization of Negative Skin friction induced on the pile. Finally experimental and numerical studies are conducted to examine the effect of applied transient live load on pile subject to Negative Skin friction.
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behavior of pile subject to Negative Skin friction and axial load
Soils and Foundations, 2004Co-Authors: C F Leung, B K Liao, Y K Chow, R F ShenAbstract:Centrifuge model tests have been conducted to investigate the effect of Negative Skin friction on piles installed through soft clay and founded in underlying dense sand. The first test series involved the study of fundamental mechanism of piles subject to Negative Skin friction only. In these tests, Negative Skin friction was induced by self-weight consolidation of clay followed by in-flight sand surcharge placement on the clay. The second test series examined the behavior of piles subject to simultaneous Negative Skin friction and axial load. The effects of axial load on the load-transfer characteristics along a pile experiencing locked-in Negative Skin friction induced by consolidating clay are investigated in detail in this paper. The effects of pile tip condition (end-bearing or socket pile), pile socket length and magnitude of applied load on the pile are also studied.
