The complex clinical picture of beta-lactam hypersensitivity: penicillins, cephalosporins, monobactams, carbapenems, and clavams

Drug-induced hypersensitivity reactions in a Lebanese outpatient population: A decade-long retrospective analysis (2012-2021)

Background

Drug hypersensitivity reactions (DHRs) are becoming more common as a result of increasing prevalence and case complexity. Allergists and clinical immunologists worldwide are challenged daily to adequately diagnose and manage these reactions. Data in the literature regarding DHR outpatient consultations are scarce worldwide, limited in the Middle East, and currently unavailable in Lebanon.

Objective

This retrospective study aimed to evaluate the characteristics of all reported DHRs over 10 years in a tertiary-care allergy clinic in Lebanon.

Methods

We conducted a decade-long (2012-21) retrospective analysis of the archived medical records of patients with a history of DHRs. Demographics, clinical history, diagnostic tools, and characteristics of the DHRs were collected and analyzed.

Results

A total of 758 patients experienced DHRs to therapeutic molecules provided for ambulatory care. Our results identified 72 medications. The most frequently implicated drug classes included β-lactam antibiotics (53.8%), followed closely by nonsteroidal anti-inflammatory drugs (48.9%). Of the 758 patients, 32.6% reported DHRs to multiple molecules, and 11.8% reported concomitant DHRs to 1 or several molecules provided in the perioperative setting. Of those, opioids and neuromuscular blocking agents were the 2 most common therapeutic classes. Furthermore, we evaluated the cross-reactivity between molecules of the same class. In neuromuscular blocking agents, rocuronium and cisatracurium were the most commonly cross-reactive, and for opioids, the most common association we recorded was with morphine and pethidine.

Conclusion

Our findings constitute the first step toward a more comprehensive evaluation of the clinical characteristics of DHRs in Lebanon.

Approach for delabeling beta-lactam allergy in children

A considerable number of pediatric patients treated with beta-lactam (BL) antibiotics develop delayed onset of skin rashes during the course of treatment. Although the most frequent cause of these symptoms is infectious, many cases are labeled as allergic reactions to these drugs. BL allergy labels could have a negative impact, as they imply avoidance of this group of drugs and the use of second-line antibiotics, leading to a potential increase in adverse effects and the utilization of less effective therapies. This constitutes a major public health concern and economic burden, as the use of broad-spectrum antibiotics can result in multidrug-resistant organisms and prolonged hospital stays. Therefore, it is crucial to delabel patients during childhood to avoid false labeling in adult life. Although the label of BL allergy is among the most frequent causes of allergy referral, its management remains controversial, and new diagnostic perspectives are changing the paradigm of managing BL allergies in children. Traditionally, drug provocation testing (DPT) was exclusively performed in patients who had previously obtained negative results from skin tests (STs). However, the sensitivity of STs is low, and the role of in vitro testing in the pediatric population is not well defined. Recent studies have demonstrated the safety of direct DPT without prior ST or serum tests for pediatric patients who report a low-risk reaction to BLs, which is cost-effective. However, there is still a debate on the optimal allergic workup to be performed in children with a benign immediate reaction and the management of children with severe cutaneous adverse drug reactions. In this review, we will discuss the impact of the label of BL allergy and the role of the different tools currently available to efficiently address BL allergy delabeling in children.

Tools for Etiologic Diagnosis of Drug-Induced Allergic Conditions

Drug hypersensitivity reactions are a serious concern in clinical practice because they can be severe and result in lifelong sequelae. An accurate diagnosis and identification of the culprit drug is essential to prevent future reactions as well as for the identification of safe treatment alternatives. Nonetheless, the diagnosis can be challenging. In vivo and in vitro tests can be helpful, although none are conclusive; therefore, the tests are not usually performed in isolation but as part of a diagnostic algorithm. In addition, some in vitro tests are only available in research laboratories, and standardization has not been fully accomplished. Collaborating research is needed to improve drug hypersensitivity reaction diagnosis. In this review, we update the current available in vivo and in vitro tools with their pros and cons and propose an algorithm to integrate them into clinical practice.

Clavulanic Acid Is a Leading Culprit Beta-Lactam in Immediate Allergic Reactions to Penicillins

PURPOSE

Clavulanate, a beta-lactam associated with amoxicillin, is frequently prescribed in patients at all ages. Recent data implicate amoxicillin-clavulanate in up to 80% of beta-lactam allergy cases. We assessed clavulanate's role in inducing allergic reactions to this combination treatment, with a focus on selective immediate reactions.

METHODS

Adults (≥ 16 years) reporting a history of immediate reactions to amoxicillin-clavulanate were evaluated through a beta-lactam allergological workup, using modified European Academy of Allergy and Clinical Immunology guidelines. Patients first underwent skin testing, and if negative, drug provocation tests. Expected outcomes were: Group A, subjects with immediate reaction to classical penicillin group determinants (penicilloyl polylysine, minor determinants mixture, and/or penicillin G); Group B, subjects with selective immediate reaction to amoxicillin; Group C, subjects with selective immediate reaction to clavulanate and Group D, those immediate reactions with co-sensitization to clavulanate plus penicillin group determinants or amoxicillin.

RESULTS

Of 1,170 included patients, 104 had immediate reactions: 36.5% to penicillin group determinants (Group A), 26.9% to amoxicillin (Group B), 32.7% to clavulanate (Group C), and 3.8% to clavulanate plus penicillin determinants or amoxicillin (Group D). Diagnosis was made by skin testing in 79%, 75% and 47% of the patients, respectively, in the first 3 groups (P < 0.001). Drug provocation tests were necessary to establish most other diagnoses. Anaphylaxis predominated over urticaria/angioedema in all groups.

CONCLUSIONS

Selective immediate reactions to clavulanate accounted for over a third of cases with confirmed reactions after amoxicillin-clavulanate intake, with more than half experiencing anaphylaxis. Within this group, skin test sensitivity was below 50%. People taking amoxicillin-clavulanate may also be co-sensitized to both drugs.

Development and Validation for Quantification of Cephapirin and Ceftiofur by Ultraperformance Liquid Chromatography with Triple Quadrupole Mass Spectrometry

Cross contamination of β-lactams is one of the highest risks for patients using pharmaceutical products. Penicillin and some non-penicillin β-lactams may cause potentially life-threatening allergic reactions. The trace detection of β-lactam antibiotics in cleaning rinse solutions of common reactors and manufacturing aids in pharmaceutical facilities is very crucial. Therefore, the common facilities adopt sophisticated cleaning procedures and develop analytical methods to assess traces of these compounds in rinsed solutions. For this, a highly sensitive and reproducible ultra-performance liquid chromatography with triple quadrupole mass spectrometry (UHPLC-MS/MS) method was developed for the analysis of Cephapirin and Ceftiofur. As per the FDA guidelines described in FDA-2011-D-0104, the contamination of these β-lactam antibiotics must be regulated. The analysis was performed on an XBridge C18 column with 100 mm length, 4.6 mm diameter, and 3.5 µm particle size at an oven temperature of about 40 °C. The mobile phase was composed of 0.15% formic acid in water and acetonitrile as mobile phases A and B, and a flow rate was set to 0.6 mL/min. The method was validated for Cephapirin and Ceftiofur. The quantification precision and accuracy were determined to be the lowest limit of detection 0.15 parts per billion (ppb) and the lowest limit of quantification 0.4 ppb. This method was linear in the range of 0.4 to 1.5 ppb with the determination of coefficient (R2 > 0.99). This sensitive and fast method was fit-for-purpose for detecting and quantifying trace amounts of β-lactam contamination, monitoring cross contamination in facility surface cleaning, and determining the acceptable level of limits for regulatory purposes.

Antibiotic Allergy De-Labeling: A Pathway against Antibiotic Resistance

Antibiotics are one of the most frequently prescribed drugs. Unfortunately, they also are the most common cause for self-reported drug allergy, limiting the use of effective therapies. However, evidence shows that more than 90% of patients labeled as allergic to antibiotics are not allergic. Importantly, the label of antibiotic allergy, whether real or not, constitutes a major public health problem as it directly impacts antimicrobial stewardship: it has been associated with broad-spectrum antibiotic use, often resulting in the emergence of bacterial resistance. Therefore, an accurate diagnosis is crucial for de-labeling patients who claim to be allergic but are not really allergic. This review presents allergy methods for achieving successful antibiotic allergy de-labeling. Patient clinical history is often inaccurately reported, thus not being able to de-label most patients. In vitro testing offers a complementary approach but it shows limitations. Immunoassay for quantifying specific IgE is the most used one, although it gives low sensitivity and is limited to few betalactams. Basophil activation test is not validated and not available in all centers. Therefore, true de-labeling still relies on in vivo tests including drug provocation and/or skin tests, which are not risk-exempt and require specialized healthcare professionals for results interpretation and patient management. Moreover, differences on the pattern of antibiotic consumption cause differences in the diagnostic approach among different countries. A multidisciplinary approach is recommended to reduce the risks associated with the reported penicillin allergy label.

Culprit Medications and Risk Factors Associated with Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: Population-Based Nested Case-Control Study

OBJECTIVE

Our objective was to describe the incidence of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) in a large unselected cohort, to validate the culprit drugs involved and the frequency of SJS/TEN for each drug, and to analyze the clinical risk factors for SJS/TEN.

METHODS

Using the computerized database of Clalit Health Services, we identified all adult patients with a new SJS/TEN diagnosis between 1 January, 2008 and 30 June, 2019 and validated each case. Cumulative incidence of SJS/TEN for each culprit drug was calculated by dividing the number of valid cases by the total number of new users of the drug in the study period. Using risk-set sampling, 20 controls were matched to each case by sex and age on the index date for a nested case-control analysis. Multivariable conditional logistic regression was used to estimate the odds ratio and 95% confidence interval for the association of incident SJS/TEN with chronic diseases.

RESULTS

We identified 87 adult cases of true/probable SJS/TEN between 1 January, 2008 and 30 June, 2019. Culprit drugs [with ALDEN scores ascertained as at least probable (≥ 4)] associated with the highest absolute risks were phenytoin, lamotrigine, and allopurinol with 3.56, 2.82, and 1.10 SJS/TEN cases/10,000 new users, respectively. Additional drugs with mean ALDEN scores ≥ 4 were sunitinib, sulfasalazine, carbamazepine, etoricoxib, etodolac, and cefuroxime, cumulative incidence: 13.57, 0.72, 0.32, 0.05, 0.02, and 0.02/10,000 new users, respectively. Previous diagnosis of systemic lupus erythematosus, psoriasis, previous drug allergies, epilepsy, malignancy, history of cerebrovascular accident, and history of diabetes mellitus were associated with an increased risk for SJS/TEN, odds ratios (95% confidence interval):17.41 (1.31-230.72), 10.28 (3.61-29.31), 5.21 (2.95-9.19), 4.92 (1.88-12.85), 3.17 (1.77-5.66), 2.61 (1.26-5.41), and 1.98 (1.12-3.53), respectively.

CONCLUSIONS

Attention should be drawn to drugs assessed by high ALDEN scores that were associated with high absolute risks for SJS/TEN. Psoriasis, former drug allergies, in addition to systemic lupus erythematosus, malignancy, history of cerebrovascular accident, and diabetes mellitus were associated with increased SJS/TEN risk in our analysis.

Isolierte Zungenschwellung nach Penizillin und negative Allergieabklärung – alles in Butter?

Penizilline können alle Arten spezifischer Immunreaktionen nach der erweiterten Coombs- und Gell-Klassifikation auslösen und zählen zu den häufigsten Ursachen unerwünschter Arzneimittelreaktionen. Das diagnostische Armamentarium umfasst neben den verschiedenen Hauttesten den Nachweis spezifischer IgE gegen allergene Determinanten am Betalaktam-Molekül und ggf. zelluläre Aktivierungsteste. Im Fall negativer Ergebnisse bei den genannten Testen kann ggf. noch die Toleranz im Rahmen eines Provokationstestes nachgewiesen werden. Die Sensitivität der diagnostischen Teste ist – mit Ausnahme des Provokationstests – aber limitiert, und falsch negative Teste sind möglich. Wir präsentieren zwei Fälle mit einer isolierten Zungenschwellung nach Gabe von Amoxicillin bei vollständig negativem, wiederholtem allergologischen Work-up. Bei beiden Patienten konnte die Überempfindlichkeit nur mit einer Reexposition nachgewiesen werden.

An EAACI Task Force report on allergy to beta-lactams in children: Clinical entities and diagnostic procedures

Beta-lactam (BL) allergy suspicion is common in children and constitutes a major public health problem, with an impact on patient's health and on medical costs. However, it has been found that most of these reactions are not confirmed by a complete allergic workup. The diagnostic value of the currently available allergy tests has been investigated intensively recently by different groups throughout the world. This has led to major changes in the management of children with a suspected BL allergy. Particularly, it is now well accepted that skin tests can be skipped before the drug provocation test in children with a benign non-immediate reaction to BL. However, there is still a debate on the optimal allergic workup to perform in children with a benign immediate reaction. In addition, management of children with severe cutaneous adverse drug reactions remains difficult. In this review, based on a selection of the most relevant studies found in the literature, we will review and discuss the diagnosis of different forms of BL allergy in children.

Risk factors of beta-lactam anaphylaxis in Korea: A 6-year multicenter retrospective adult case-control study

Background

Beta-lactams (BLs) are commonly used antibiotics and leading causative agents of drug-induced anaphylaxis. Few studies on the culprit drugs and risk factors of BL-induced anaphylaxis are available. Our goal was to evaluate the culprit drugs and compare the risk factors in patients with BL-induced anaphylaxis to matched tolerant controls in a hospital setting.

Methods

We retrospectively enrolled all patients who developed anaphylaxis from intravenous BL during hospitalization from 9 Korean hospitals. We compared clinical parameters between patients with BL-induced anaphylaxis and 4-fold BL-tolerant controls matched by age, sex, BL use, and the purpose of BL administration.

Results

Seventy-four cases of BL-induced anaphylaxis and 296 BL-tolerant controls were enrolled. Cephalosporin accounted for 77% of total BL-induced anaphylaxis, and the top derivatives were ceftriaxone (23.0%), cefazedone (10.8%), and cefbuperazone (9.5%). Among penicillin derivatives, piperacillin (16.2%) was the most common, followed by ampicillin (2.7%). History of drug allergy (odds ratio [OR], 19.91; 95% confidence interval [CI] 5.33–74.44), previous exposure to the causative BL (OR, 7.71; 95% CI, 1.62–36.76), and concurrent administration of angiotensin-converting enzyme inhibitors (ACEIs) (OR, 5.97; 95% CI, 1.28–27.91) were independent risk factors associated with BL-induced anaphylaxis. Food allergy (OR, 13.93; 95% CI 1.31–148.9) and previous exposure to BL (OR, 6.59; 95% CI, 1.30–33.31) were identified as risk factors for cephalosporin-induced anaphylaxis.

Conclusions

To prevent BL-induced anaphylaxis, attention should be paid to histories of drug or food allergy, previous exposure to BLs, and ACEI use. The risk factors and clinical outcomes might vary according to the BL classes.

Variability of the Genes Involved in the Cellular Redox Status and Their Implication in Drug Hypersensitivity Reactions

Adverse drug reactions are a major cause of morbidity and mortality. Of the great diversity of drugs involved in hypersensitivity drug reactions, the most frequent are non-steroidal anti-inflammatory drugs followed by β-lactam antibiotics. The redox status regulates the level of reactive oxygen and nitrogen species (RONS). RONS interplay and modulate the action of diverse biomolecules, such as inflammatory mediators and drugs. In this review, we address the role of the redox status in the initiation, as well as in the resolution of inflammatory processes involved in drug hypersensitivity reactions. We summarize the association findings between drug hypersensitivity reactions and variants in the genes that encode the enzymes related to the redox system such as enzymes related to glutathione: Glutathione S-transferase (GSTM1, GSTP, GSTT1) and glutathione peroxidase (GPX1), thioredoxin reductase (TXNRD1 and TXNRD2), superoxide dismutase (SOD1, SOD2, and SOD3), catalase (CAT), aldo-keto reductase (AKR), and the peroxiredoxin system (PRDX1, PRDX2, PRDX3, PRDX4, PRDX5, PRDX6). Based on current evidence, the most relevant candidate redox genes related to hypersensitivity drug reactions are GSTM1, TXNRD1, SOD1, and SOD2. Increasing the understanding of pharmacogenetics in drug hypersensitivity reactions will contribute to the development of early diagnostic or prognosis tools, and will help to diminish the occurrence and/or the severity of these reactions.

β-Lactam Allergy and Cross-Reactivity: A Clinician's Guide to Selecting an Alternative Antibiotic

β-Lactams which include penicillins, cephalosporins, carbapenems, and monobactams are the most common antibiotic classes reported to cause allergic reactions to drugs. This review is mainly about published studies assessing the cross-reactivity among β-lactams in penicillin- or cephalosporin-allergic subjects by carrying out diagnostic tests with alternative β-lactams and, if appropriate, graded challenges. Several studies demonstrated that cross-reactivity connected with the β-lactam ring, causing positive responses to allergy tests with all β-lactams, is infrequent in subjects with an IgE-mediated allergy and anecdotal in those with a T-cell-mediated allergy. Identities or similarities of β-lactam side-chain structures are mainly responsible for cross-reactivity among these antibiotics. For example, in aminopenicillin-allergic subjects, cross-reactivity with aminocephalosporins could possibly be over 30%. On the other hand, in a few prospective studies of penicillin-allergic individuals, less than 1% of cases show a cross-reactivity between penicillins and both aztreonam and carbapenems. Particular patterns of allergy-test positivity observed in some studies that assessed cross-reactivity among β-lactams seem to indicate that prior exposures may be responsible for coexisting sensitivities. Therefore, pre-treatment skin tests with the related β-lactams are suggested before administering them via graded challenges to β-lactam-allergic patients who need alternative β-lactams.

Penicillin and cephalosporin cross-reactivity: role of side chain and synthetic cefadroxil epitopes

BACKGROUND

Analysis of cross-reactivity is necessary for prescribing safe cephalosporins for penicillin allergic patients. Amoxicillin (AX) is the betalactam most often involved in immediate hypersensitivity reactions (IHRs), and cefadroxil (CX) the most likely cephalosporin to cross-react with AX, since they share the same R1 side chain, unlike cefuroxime (CO), with a structurally different R1. We aimed to analyse cross-reactivity with CX and CO in patients with confirmed IHRs to AX, including sIgE recognition to AX, CX, CO, and novel synthetic determinants of CX.

METHODS

Fifty-four patients with confirmed IHRs to AX based on skin test (ST) and/or drug provocation test (DPT) were included. Serum sIgE to AX and benzylpenicillin was determined by Radioallergosorbent test (RAST). Two potential determinants of CX, involving intact or modified R1 structure, with open betalactam ring, were synthesised and sIgE evaluated by RAST inhibition assay.

RESULTS

Tolerance to CX (Group A) was observed in 64.8% cases and cross-reactivity in 35.2% cases (Group B). Cross-reactivity with CO was only found in 1.8% cases from Group B. ST to CX showed a negative predictive value of 94.6%. RAST inhibition assays showed higher recognition to CX as well as to both synthetic determinants (66% of positive cases) in Group B.

CONCLUSIONS

Cross-reactivity with CX in AX allergic patients is 35%, being ST not enough for prediction. R1, although critical for recognition, is not the unique factor. The synthetic determinants of CX, 1-(HOPhG-Ser-Bu) and 2-(pyrazinone) are promising tools for determining in vitro cross-reactivity to CX in AX allergic patients.

The use of direct oral challenge to confirm allergies to penicillin class antibiotics in Danish children

Background

A high number of children are referred to pediatric departments with a suspected allergic reaction to antibiotics. The prevalence of true allergy is considered to be significantly lower than shown from clinical history and symptoms alone. This study investigated the historical use of direct oral challenges at three specialist pediatric departments in Denmark.

Methods

In this retrospective medical record review study, 141 children (69 boys and 72 girls) with a clinical history of suspected penicillin class allergy were investigated. A standardized questionnaire for drug allergy was completed in the beginning of the investigation, which also included a skin prick test (SPT), measurement of IgE to different types of penicillin, and a drug challenge (DC).

Results

Only four (2.8%) of the patients referred for further investigation in our study had a positive DC. We found no correlation between a positive DC, positive SPT or elevated specific IgE. None of the patients with a positive DC reacted with a rash alone prior to investigation.

Conclusions

Allergy to penicillin in children is rare and probably overestimated. In children reacting to penicillin with a rash alone, our study indicated that the rash was probably not related to allergy and treatment should thus be continued.

The use of in vivo and in vitro tests in children with beta lactam allergy

BACKGROUND

Drug allergies are reactions within the context of drug hypersensitivity reactions, which are caused by immunological mechanisms due to a previously sensitising drug. Beta-lactam antibiotics (BLA) are the leading agents causing drug hypersensitivity reactions in children. The aim of this study is to evaluate the diagnostic importance of in vivo and in vitro diagnostic tests in children with suspected immediate-type BLA hypersensitivity and to investigate the frequency of their use for the final diagnosis.

METHODS

Patients admitted to the Outpatient Clinic of Division of Paediatric Allergy and Immunology with suspicion of immediate-type BLA hypersensitivity between December 2014 and December 2018 were investigated. Patients with a history of immediate reactions to BLA were examined by performing drug specific IgE, skin prick tests, intradermal tests and drug provocation tests (DPT).

RESULTS

During the study period, 148 patients were admitted to our clinic with suspected immediate-type BLA hypersensitivity. Forty-eight patients completed all assessment steps and were enrolled in the study. It has been shown that 27 patients did not have drug allergy. BLA hypersensitivity was proven in 21 patients by using in vivo test algorithm. More than half of the patients were diagnosed via skin tests with culprit drug.

CONCLUSION

Allergy work-up should be performed in patients with immediate reactions to BLA. A skin test can demonstrate BLA hypersensitivity in most patients. Thus, skin tests should be performed prior to the drug provocation test.

Minimal agreement between basophil activation test and immunoassay in diagnosis of penicillin allergy

INTRODUCTION

Basophil activation test (BAT) and immunoassays are the most widely used in vitro tests to diagnose IgE-mediated allergic reactions to penicillin. However, studies to determine if one test is interdependent from another are limited.

OBJECTIVE

The present study aimed to measure the agreement between BAT and immunoassay in diagnosis of penicillin allergy.

METHOD

BAT was performed using penicillin G (Pen G), penicillin V (Pen V), penicilloyl-polylysine (PPL), minor determinant mix (MDM), amoxicillin (Amx) and ampicillin (Amp) in 25 patients. Immunoassay of total IgE (tIgE) and specific IgE (sIgE) antibodies to Pen G, Pen V, Amx and Amp were quantified. Skin prick test (SPT) using PPL-MDM, Amx, Amp and Clavulanic acid were also performed.

RESULTS

Minimal agreement was observed between BAT and immunoassay (k=0.25). Of two BAT-positive patients, one patient is positive to Amx (59.27%, SI=59) and Amp (82.32%, SI=82) but sIgE-negative to all drug tested. This patient is also SPT-positive to both drugs. Another patient is BAT-positive to Pen G (10.18%, SI=40), Pen V (25.07%, SI=100) and Amp (19.52%, SI=79). In sIgE immunoassay, four patients were sIgE-positive to at least one of the drugs tested. The sIgE level of three patients was between low and moderate and they were BAT-negative. One BAT-positive patient had a high level of sIgE antibodies (3.50-17.5kU/L) along with relatively high specific to total IgE ratio ≥0.002 (0.004-0.007).

CONCLUSIONS

The agreement between BAT and immunoassay is minimal. Performing both tests provides little increase in the sensitivity of allergy diagnosis work-up for immediate reactions to penicillin.

Non-Surgical Periodontal Therapy with Adjunctive Amoxicillin/Metronidazole or Metronidazole When No Aggregatibacter actinomycetemcomitans Is Detected—A Randomized Clinical Trial

Background: The aim was to compare two different systemic antibiotics regimens adjunctive to non-surgical periodontal therapy when Aggregatibacter actinomycetemcomitans was not detected in the subgingival biofilm. Methods: A total of 58 patients with periodontitis and with no A. actinomycetemcomitans in the subgingival biofilm were treated with full-mouth subgingival instrumentation and either metronidazole (MET; n = 29) or amoxicillin/metronidazole (AMX/MET; n = 29). Probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BOP) were recorded at baseline, as well as after three and six months. Subgingival biofilm and gingival crevicular fluid were collected and analyzed for major periodontopathogens and biomarkers. Results: PD, CAL and BOP improved at 3 and 6 months (each p < 0.001 vs. baseline) with no difference between the groups. Sites with initial PD ≥ 6 mm also improved in both groups after 3 and 6 months (p < 0.001) with a higher reduction of PD in the AMX/MET group (p < 0.05). T. forsythia was lower in the AMX/MET group after 3 months (p < 0.05). MMP-8 and IL-1β were without significant changes and differences between the groups. Conclusion: When A. actinomycetemcomitans was not detected in the subgingival biofilm, the adjunctive systemic use of amoxicillin/metronidazole results in better clinical and microbiological outcomes of non-surgical periodontal therapy when the application of systemic antibiotics is scheduled.

Implementation of a pharmacist-led penicillin allergy de-labelling service in a public hospital

BACKGROUND

Inaccurate allergy labelling results in inappropriate antimicrobial management of the patient, which may affect clinical outcome, increase the risk of adverse events and increase costs. Inappropriate use of alternative antibiotics has implications for antimicrobial stewardship programmes and microbial resistance.

METHODS

All adult inpatients labelled as penicillin allergic were identified and screened for eligibility by the study pharmacist. An accurate allergy and medication history was taken. Patients were 'de-labelled', underwent oral challenge or were referred to an immunology clinic, if study criteria were met. All patients included in the study were followed-up 1 year after intervention.

RESULTS

Two hundred and fifty eligible patients with a label of 'penicillin allergy' were identified. The prevalence of reported penicillin allergy at Middlemore Hospital was 11%. We found that 80% of study patients could be 'de-labelled'. Of those, 80% were 'de-labelled' after an interview with the pharmacist alone, 16% had an uneventful oral challenge and 4% were deemed to be inappropriately labelled after referral to an immunology clinic. Appropriately labelled patients accounted for 20% of the study population. Changes to inpatient antibiotic therapy were recommended in 61% of 'de-labelled' patients, of which no patients had adverse events after commencing on penicillin antibiotics. At the 1 year follow-up, 98% of patients who were 'de-labelled' had no adverse events to repeated administration of penicillin antibiotics.

CONCLUSIONS

This study showed that a pharmacist-led allergy management service is a safe option to promote antimicrobial stewardship and appropriate allergy labelling.

Usefulness of an Artificial Neural Network in the Prediction of β-Lactam Allergy

BACKGROUND

An accurate diagnosis of β-lactam (BL) allergy improves the use of antibiotics, increases patients' safety, and reduces costs to health systems. Nevertheless, it requires skin and drug provocation tests, which are time-consuming and put the patient at risk. Furthermore, allergy testing is not available in circumstances such as the urgent need for antibiotic therapy.

OBJECTIVE

To evaluate the usefulness of an artificial neural network (ANN) in the prediction of hypersensitivity to BLs, and compare it with logistic regression (LR) analysis.

METHODS

In a single-center study, 656 patients evaluated for BL allergy between 1994 and 2000 were retrospectively analyzed, and the data were used to construct an ANN. The ANN predictive capabilities were compared with LR and then prospectively evaluated in 615 patients who underwent BL evaluation between 2011 and 2017.

RESULTS

A total of 1271 patients were evaluated. All patients had a definite diagnosis as allergic or nonallergic to BL. The prospective sample showed a lower percentage of patients with allergy than the retrospective sample (20.7% vs 25.8%; P = .018). In the retrospective and prospective series, the ANN reached a sensitivity of 89.5% and 81.1%, a specificity of 86.1% and 97.9%, a positive predictive value of 82.1% and 91.1%, and a negative predictive value of 92.1% and 95.2%, respectively. The ANN's performance was far superior to that of the LR, whose best performance reached a sensitivity of 31.9% and a specificity of 98.8%.

CONCLUSIONS

This ANN demonstrated a superior performance than the LR in predicting BL hypersensitivity without misdiagnosing severe allergic reactions. The ANN could be a helpful tool to classify the reaction risk, particularly in the identification of low-risk patients, in which an open challenge could be done to delabel patients.

A comparison of different antibiotic regimens for the treatment of infective endocarditis

BACKGROUND

Infective endocarditis is a microbial infection of the endocardial surface of the heart. Antibiotics are the cornerstone of treatment, but due to the differences in presentation, populations affected, and the wide variety of micro-organisms that can be responsible, their use is not standardised. This is an update of a review previously published in 2016.

OBJECTIVES

To assess the existing evidence about the clinical benefits and harms of different antibiotics regimens used to treat people with infective endocarditis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase Classic and Embase, LILACS, CINAHL, and the Conference Proceedings Citation Index - Science on 6 January 2020. We also searched three trials registers and handsearched the reference lists of included papers. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing the effects of antibiotic regimens for treating definitive infective endocarditis diagnosed according to modified Duke's criteria. We considered all-cause mortality, cure rates, and adverse events as the primary outcomes. We excluded people with possible infective endocarditis and pregnant women.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment, and data extraction in duplicate. We constructed 'Summary of findings' tables and used GRADE methodology to assess the quality of the evidence. We described the included studies narratively.

MAIN RESULTS

Six small RCTs involving 1143 allocated/632 analysed participants met the inclusion criteria of this first update. The included trials had a high risk of bias. Three trials were sponsored by drug companies. Due to heterogeneity in outcome definitions and different antibiotics used data could not be pooled. The included trials compared miscellaneous antibiotic schedules having uncertain effects for all of the prespecified outcomes in this review. Evidence was either low or very low quality due to high risk of bias and very low number of events and small sample size. The results for all-cause mortality were as follows: one trial compared quinolone (levofloxacin) plus standard treatment (antistaphylococcal penicillin (cloxacillin or dicloxacillin), aminoglycoside (tobramycin or netilmicin), and rifampicin) versus standard treatment alone and reported 8/31 (26%) with levofloxacin plus standard treatment versus 9/39 (23%) with standard treatment alone; risk ratio (RR) 1.12, 95% confidence interval (CI) 0.49 to 2.56. One trial compared fosfomycin plus imipenem 3/4 (75%) versus vancomycin 0/4 (0%) (RR 7.00, 95% CI 0.47 to 103.27), and one trial compared partial oral treatment 7/201 (3.5%) versus conventional intravenous treatment 13/199 (6.53%) (RR 0.53, 95% CI 0.22 to 1.31). The results for rates of cure with or without surgery were as follows: one trial compared daptomycin versus low-dose gentamicin plus an antistaphylococcal penicillin (nafcillin, oxacillin, or flucloxacillin) or vancomycin and reported 9/28 (32.1%) with daptomycin versus 9/25 (36%) with low-dose gentamicin plus antistaphylococcal penicillin or vancomycin; RR 0.89, 95% CI 0.42 to 1.89. One trial compared glycopeptide (vancomycin or teicoplanin) plus gentamicin with cloxacillin plus gentamicin (13/23 (56%) versus 11/11 (100%); RR 0.59, 95% CI 0.40 to 0.85). One trial compared ceftriaxone plus gentamicin versus ceftriaxone alone (15/34 (44%) versus 21/33 (64%); RR 0.69, 95% CI 0.44 to 1.10), and one trial compared fosfomycin plus imipenem versus vancomycin (1/4 (25%) versus 2/4 (50%); RR 0.50, 95% CI 0.07 to 3.55). The included trials reported adverse events, the need for cardiac surgical interventions, and rates of uncontrolled infection, congestive heart failure, relapse of endocarditis, and septic emboli, and found no conclusive differences between groups (very low-quality evidence). No trials assessed quality of life.

AUTHORS' CONCLUSIONS

This first update confirms the findings of the original version of the review. Limited and low to very low-quality evidence suggests that the comparative effects of different antibiotic regimens in terms of cure rates or other relevant clinical outcomes are uncertain. The conclusions of this updated Cochrane Review were based on few RCTs with a high risk of bias. Accordingly, current evidence does not support or reject any regimen of antibiotic therapy for the treatment of infective endocarditis.

Drugs frequently involved in inducing hypersensitivity reactions

Adverse drug reactions represent a major public health problem, both from an economic point of view and, mainly, from the point of view of the induced pathology (iatrogenic diseases), being difficult to differentiate from other pathological conditions or even from the treated disease. Thus, these aspects prevent the use of the first-choice drugs needed for a particular treatment, in different therapeutic classes: beta-lactam antibiotics; sulfonamides; macrolide antibiotics; quinolones; non-steroidal anti-inflammatories; corticosteroids; Angiotensin converting enzyme (ACE) inhibitors; general anesthetics; biological drugs; antiepileptic drugs etc. On the other hand, adverse drug reactions represent a major problem for both clinical practice and preclinical research, in order to develop new drugs. Hypersensitivity reactions mainly refer to the adverse effects that can be harmful, disturbing, and sometimes fatal, that appear under the conditions of a normal immune system, including allergies and autoimmune reactions, both triggered by an immunological-allergic mechanism. The main purpose of this paper is to review the main classes of drugs involved in inducing hypersensitivity reactions.

Characterisation of the β-lactam resistance enzyme in Acanthamoeba castellanii

β-Lactams are well known as the best antibiotics for inhibiting the cross-linking between adjacent polysaccharide chains and peptides in the peptidoglycan layer of bacterial cell walls, causing bacterial cell lysis. There are no reports on the action of and resistance mechanisms to β-lactams in protozoa. Acanthamoeba castellanii is a free-living protozoan pathogen capable of causing blinding keratitis and fatal granulomatous encephalitis. When Acanthamoeba is exposed to harsh conditions, it differentiates into the cyst stage to avoid environmental stresses, such as drug treatment. In this study, it was shown that the mature encystation rate of A. castellanii is decreased by treatment with cefotaxime (CTX) and clavulanic acid (CLA); however, the drugs do not kill the amoeba. We hypothesise that β-lactam antibiotics may disturb synthesis of the double cell wall during the encystation process of Acanthamoeba. Interestingly, CTX is considered a powerful β-lactam, whereas CLA is considered a weak β-lactam but an efficient β-lactamase inhibitor. It was demonstrated that Acanthamoeba expresses β-lactamases to prevent inhibition of the encystation process by β-lactams. To reveal the functions of Acanthamoeba β-lactamases, a recombinant Acanthamoeba β-lactamase was produced in Escherichia coli that conferred resistance to β-lactams such as CTX, cefuroxime, penicillin and meropenem. Consequently, we suggest that Acanthamoeba produces enzymes similar to β-lactamases to avoid interference from the environment. Here we provide a new point of view on an important gene responsible for drug resistance and advocate for the development of more efficient treatment against Acanthamoeba infection.

Once-daily oral omadacycline versus twice-daily oral linezolid for acute bacterial skin and skin structure infections (OASIS-2): a phase 3, double-blind, multicentre, randomised, controlled, non-inferiority trial

BACKGROUND

Pathogen resistance and safety concerns limit oral antibiotic options for the treatment of acute bacterial skin and skin structure infections (ABSSSI). We aimed to compare the efficacy and safety of once-daily oral omadacycline, an aminomethylcycline antibiotic, versus twice-daily oral linezolid for treatment of ABSSSI.

METHODS

In this phase 3, double-blind, randomised, non-inferiority study, eligible adults with ABSSSI at 33 sites in the USA were randomly assigned (1:1) to receive omadacycline (450 mg orally every 24 h over the first 48 h then 300 mg orally every 24 h) or linezolid (600 mg orally every 12 h) for 7-14 days. Randomisation was done via an interactive response system using a computer-generated schedule, and stratified by type of infection (wound infection, cellulitis or erysipelas, or major abscess) and receipt (yes or no) of allowed previous antibacterial treatment. Investigators, funders, and patients were masked to treatment assignments. Primary endpoints were early clinical response, 48-72 h after first dose, in the modified intention-to-treat (mITT) population (randomised patients without solely Gram-negative ABSSSI pathogens at baseline), and investigator-assessed clinical response at post-treatment evaluation, 7-14 days after the last dose, in the mITT population and clinically evaluable population (ie, mITT patients who had a qualifying infection as per study-entry criteria, received study drug, did not receive a confounding antibiotic, and had an assessment of outcome during the protocol-defined window). The safety population included randomised patients who received any amount of study drug. We set a non-inferiority margin of 10%. This study is registered with ClinicalTrials.gov, NCT02877927, and is complete.

FINDINGS

Between Aug 11, 2016, and June 6, 2017, 861 participants were assessed for eligibility. 735 participants were randomly assigned, of whom 368 received omadacycline and 367 received linezolid. Omadacycline (315 [88%] of 360) was non-inferior to linezolid (297 [83%] of 360) for early clinical response (percentage-point difference 5·0, 95% CI -0·2 to 10·3) in the mITT population. For investigator-assessed clinical response at post-treatment evaluation, omadacycline was non-inferior to linezolid in the mITT (303 [84%] of 360 vs 291 [81%] of 360; percentage-point difference 3·3, 95% CI -2·2 to 9·0) and clinically evaluable (278 [98%] of 284 vs 279 [96%] of 292; 2·3, -0·5 to 5·8) populations. Mild to moderate nausea and vomiting were the most frequent treatment-emergent adverse events in omadacycline (111 [30%] of 368 and 62 [17%] of 368, respectively) and linezolid (28 [8%] of 367 and 11 [3%] of 367, respectively) groups.

INTERPRETATION

Once-daily oral omadacycline was non-inferior to twice-daily oral linezolid in adults with ABSSSI, and was safe and well tolerated. Oral-only omadacycline represents a new treatment option for ABSSSI, with potential for reduction in hospital admissions and cost savings.

FUNDING

Paratek Pharmaceuticals.

Antibiotic therapy for adults with neurosyphilis

BACKGROUND

Neurosyphilis is an infection of the central nervous system, caused by Treponema pallidum, a spirochete capable of infecting almost any organ or tissue in the body causing neurological complications due to the infection. This disease is a tertiary manifestation of syphilis. The first-line treatment for neurosyphilis is aqueous crystalline penicillin. However, in cases such as penicillin allergy, other regimes of antibiotic therapy can be used.

OBJECTIVES

To assess the clinical effectiveness and safety of antibiotic therapy for adults with neurosyphilis.

SEARCH METHODS

We searched the Cochrane Library, CENTRAL, MEDLINE, Embase, LILACS, World Health Organization International Clinical Trials Registry Platform and Opengrey up to April 2019. We also searched proceedings of eight congresses to a maximum of 10 years, and we contacted trial authors for additional information.

SELECTION CRITERIA

We included randomised clinical trials that included men and women, regardless of age, with definitive diagnoses of neurosyphilis, including HIV-seropositive patients. We compared any antibiotic regime (concentration, dose, frequency, duration), compared to any other antibiotic regime for the treatment for neurosyphilis in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected eligible trials, extracted data, and evaluated risk of bias. We resolved disagreements by involving a third review author. For dichotomous data (serological cure, clinical cure, adverse events), we presented results as summary risk ratios (RR) with 95% confidence intervals (CI). We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

We identified one trial, with 36 participants​ diagnosed ​with syphilis and HIV. The participants were mainly men, with a median age of 34 years. This trial, ​funded by a pharmaceutical company, compared ceftriaxone in 18 participants (2 g daily for 10 days), with penicillin G, also in 18 participants (4 million/Units (MU)/intravenous (IV) every 4 hours for 10 days). The trial reported incomplete and inconclusive results. Three of 18 (16%) participants receiving ceftriaxone versus 2 of 18 (11%) receiving penicillin G achieved serological cure (RR 1.50; 95% CI: 0.28 to 7.93; 1 trial, 36 participants very low-quality evidence); and 8 of 18 (44%) participants receiving ceftriaxone versus 2 of 18 (18%) participants receiving penicillin G achieved clinical cure (RR 4.00; 95% CI: 0.98 to 16.30; 1 trial, 36 participants very low-quality evidence). Although more participants who received ceftriaxone achieved serological and clinical cure compared to those who received penicillin G, the evidence from this trial was insufficient to determine whether there was a difference between treatment with ceftriaxone or penicillin G.In this trial, the authors reported what would usually be adverse events as symptoms and signs in the follow-up of participants. Furthermore, this trial did not evaluate recurrence of neurosyphilis, time to recovery nor quality of life. We judged risk of bias in this clinical trial to be unclear for random sequence generation, allocation, ​and blinding of participants, and high for incomplete outcome data, potential conflicts of interest (funding bias), and other bias, due to the lack of a sample size calculation. We rated the quality of evidence as very low.

AUTHORS' CONCLUSIONS

Due to low quality and insufficient evidence, it was not possible to determine whether there was a difference between treatment with ceftriaxone or Penicillin G. Also, the benefits to people without HIV and neurosyphilis are unknown, as is the ceftriaxone safety profile.Therefore, these results should be interpreted with caution. This conclusion does not mean that antibiotics should not be used for treating this clinical entity. This Cochrane Review has identified the need of adequately powered trials, which should be planned according to Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) recommendations, conducted and reported as recommended by the CONSORT statement. Furthermore, the outcomes should be based on patients' perspectives taking into account Patient-Centered Outcomes Research Institute (PCORI) recommendations.

Anaphylaxis to beta-lactam antibiotics at pediatric age: Six-year survey

INTRODUCTION

Beta-lactams are the most frequently used antibiotics in pediatric age. Anaphylactic reactions may occur and need to be properly studied, but studies in children are scarce.

OBJECTIVE

Characterization of case reports of anaphylaxis in children referred to an allergy department with suspected beta-lactams hypersensitivity.

MATERIALS AND METHODS

Retrospective analysis of all children referred to our Drug Allergy Center with suspected beta-lactams hypersensitivity between January 2011 and December 2016. Description of the drug allergy work-up performed studied according to standardized diagnostic procedures of ENDA/EAACI, including specific-IgE assay, skin prick and intradermal tests and diagnostic/alternative drug challenge tests.

RESULTS

146 children with suspected beta-lactams hypersensitivity were studied, and in 21 (14.4%) the diagnosis was confirmed. In all of them, except for three children, an alternative beta-lactam was found. In seven children (33.3% of those with confirmed beta-lactams hypersensitivity) anaphylaxis was confirmed, and all of them described reactions with cutaneous and respiratory or gastrointestinal involvement. The culprit drug was amoxicillin in six and flucloxacillin in one. In this sample, we also performed oral challenge with cefuroxime, being negative in all cases. Almost all cases of confirmed anaphylaxis (six from seven cases) were IgE mediated, with positive skin tests despite negative serum specific-IgE.

CONCLUSIONS

Allergic reactions to beta-lactams, although rare in children, require a detailed clinical history and a specialized drug allergy work-up to allow a correct diagnosis as well as to avoid the possibility of a potential life-threatening reaction and provide alternative drugs.

EAACI/ENDA Position Paper: Diagnosis and management of hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs) in children and adolescents

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used in the pediatric population as antipyretics/analgesics and anti-inflammatory medications. Hypersensitivity (HS) reactions to NSAID in this age group, while similar to adults, have unique diagnostic and management issues. Although slowly accumulating, published data in this age group are still relatively rare and lacking a unifying consensus. This work is a summary of current knowledge and consensus recommendations utilizing both published data and expert opinion from the European Network of Drug Allergy (ENDA) and the Drug Hypersensitivity interest group in the European Academy of Allergy and Clinical Immunology (EAACI). This position paper summarizes diagnostic and management guidelines for children and adolescents with NSAIDs hypersensitivity.

Drug-induced anaphylaxis: is it an epidemic?

PURPOSE OF REVIEW

The present review addresses the epidemiology, analyzes the current data and promotes global awareness of drug-induced anaphylaxis.

RECENT FINDINGS

Anaphylaxis is a medical emergency that may cause death! In the last decade, studies have shown an increasing incidence and prevalence of anaphylaxis.

SUMMARY

Drug-induced anaphylaxis fatalities have increased, and this syndrome remains underdiagnosed and undertreated.

Antibiotics for treating gonorrhoea in pregnancy

BACKGROUND

Gonorrhoea is a sexually transmitted infection that is caused by Neisseria gonorrhoeae, and is a major public health challenge today. N gonorrhoeae can be transmitted from the mother's genital tract to the newborn during birth, and can cause gonococcal ophthalmia neonatorum as well as systemic neonatal infections. It can also cause endometritis and pelvic sepsis in the mother. This review updates and replaces an earlier Cochrane Review on antibiotics for treating this infectious condition.

OBJECTIVES

To assess the clinical effectiveness and harms of antibiotics for treating gonorrhoea in pregnant women.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2017), LILACS database (1982 to April 5, 2017), the WHO International Clinical Trials Registry Platform (ICTRP; April 5, 2017), ClinicalTrials.gov (April 5, 2017), the ISRCTN Registry (April 5, 2017), and Epistemonikos (April 5, 2017). We also searched reference lists of all retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing the use of antibiotics for treating gonorrhoea in pregnancy. The antibiotics could have been used alone or in combination, were administered parenterally, orally, or both, and were compared with another antibiotic.We included RCTs regardless of their publication status (published, unpublished, published as an article, an abstract, or a letter), language, or country. We applied no limits on the length of follow-up.We excluded RCTs using a cluster- or cross-over design, or quasi-RCTs.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy.

MAIN RESULTS

We included two RCTs, that randomised 514 pregnant women (347 women analysed) at a mean gestational age of 22 weeks. Both trials were conducted in the outpatient department of the same two hospitals in the USA between 1993 and 2001, and had a follow-up of 14 days. One of the trials was sponsored by a drug company. We considered both trials to be at a high risk of bias.One trial compared ceftriaxone (125 mg, intramuscular) with cefixime (400 mg, oral); the other trial had three arms, and assessed ceftriaxone (250 mg, intramuscular) versus either amoxicillin (3 g, oral) plus probenecid (1 g, oral) or spectinomycin (2 g, intramuscular). We did not include the spectinomycin data because this medication is no longer produced. We were unable to conduct meta-analysis because the trials compared different medications.We found inconclusive evidence that there were clear differences in the cure of gonococcal infections (genital, extragenital, or both) between intramuscular ceftriaxone versus oral amoxicillin plus oral probenecid (risk ratio (RR) 1.07, 95% confidence interval (CI) 0.98 to 1.16; one RCT; 168 women; very low-quality evidence) or intramuscular ceftriaxone versus oral cefixime (RR 0.99, 95% CI 0.91 to 1.08; one RCT; 95 women; very low-quality evidence).Neither of the trials reported on two of this review's primary maternal outcomes: incidence of obstetric complications (miscarriage, premature rupture of membranes, preterm delivery, or fetal death), or disseminated gonococcal infection, or on the incidence of neonatorum ophthalmia in the neonates.One trial reported one case of vomiting in the oral amoxacillin plus probenecid group. Trials reported pain at the injection sites, but did not quantify it. Hyperberbilurrubinemia was more frequent in neonates whose mothers were exposed to ceftriaxone. There were no clear differences between groups for neonatal malformation.

AUTHORS' CONCLUSIONS

This Cochrane Review found high levels of cure of gonococcal infections in pregnancy with the given antibiotic regimens. However, the evidence in this review is inconclusive as it does not support one particular regimen over another. This conclusion was based on very low-quality evidence (downgraded for poor trial design, imprecision) from two trials (involving 514 women), which we assessed to be at a high risk of bias for a number of domains. The harm profiles of the antibiotic regimes featured in this review remain unknown.High-quality RCTs are needed, with sufficient power to assess the clinical effectiveness and potential harms of antibiotics in pregnant women with gonorrhoea. These should be planned according to Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT),conducted following CONSORT recommendations, and based on Patient-Centered Outcomes Research Institute (PCORI) outcomes.

Diagnosing and managing patients with drug hypersensitivity

INTRODUCTION

Diagnosing and managing drug hypersensitivity is challenging because there are no clear limits between different types of drug reactions. Distinguishing between type A (predictable) and type B (hypersensitivity) reactions when a drug is introduced on the market is not easy. When many people use a drug, adverse reactions can occur, conditioned by diverse genetic profiles, viral infections or concomitant therapy. Occasionally the only tool clinicians have on which to base the diagnosis is the clinical history. Skins tests or in vitro tests sometimes have low sensitivity or are unavailable, and drug provocation tests may be dangerous or strictly forbidden in case of severe cutaneous reactions. Areas covered: This paper reviews the diagnosis and management of the two main types of immunological reactions: IgE-mediated immediate drug hypersensitivity reactions (IDHRs) and non-immediate drug hypersensitivity reactions (NIDHRs). Expert commentary: Although Europe and the United States use different diagnostic methods, patients with history of drug hypersensitivity must avoid the suspicious drug, and clinicians must assess tolerance to safe alternatives under medical surveillance. Sometimes desensitization may be required. There is a consensus about the need to perform genetic testing for specific drugs and give patients proper documentation to prevent future exposure to culprit drugs.

Australian and New Zealand Anaesthetic Allergy Group Perioperative Anaphylaxis Investigation Guidelines

These guidelines are a consensus document developed by a working party of the Australian and New Zealand Anaesthetic Allergy Group (ANZAAG) to provide an approach to the investigation of perioperative anaphylaxis. They focus primarily on the use of skin testing as it is the investigation with the greatest clinical utility for the identification of the likely causative agent and potentially safer alternatives. The practicalities and process of skin testing, its limitations, and the place of other tests are discussed. These guidelines also address the roles of graded challenge and in vitro testing. The implications of anaphylaxis associated with neuromuscular blocking agents, beta-lactam antibiotics, local anaesthetic agents and chlorhexidine are discussed. Evidence for the recommendations is derived from literature searches using the words skin test, allergy, anaphylaxis, anaesthesia, and each of the individual agents listed in these guidelines. The individual articles were then reviewed for suitability for inclusion in these guidelines. Where evidence was not strong, as is the situation for many perioperative agents, expert consensus from the ANZAAG working party was used. These guidelines are intended for use by specialists involved in the investigation of perioperative allergy. They have been approved following peer review by members of ANZAAG and are available on the ANZAAG website: http://www.anzaag.com/anaphylaxis-management/testing-guidelines.pdf .

In Vitro Diagnostic Testing for Antibiotic Allergy

Allergy to antibiotics is an important worldwide problem, with an estimated prevalence of up to 10% of the population. Reaction patterns for different antibiotics have changed in accordance with consumption trends. Most of the allergic reactions to antibiotics have been reported for betalactams, followed by quinolones and macrolides and, to a lesser extent, to others, such as metronidazole clindamycin and sulfonamides. The diagnostic procedure includes a detailed clinical history, which is not always possible and can be unreliable. This is usually followed by in vivo, skin, and drug provocation tests. These are not recommended for severe, potentially lifethreaten reactions or for drugs that are known to produce a high rate of false positive results. Given the limitations of in vivo tests, in vitro test can be helpful for diagnosis, despite having suboptimal sensitivity. The most highly employed techniques for diagnosing immediate reactions to antibiotics are immunoassays and basophil activation tests, while lymphocyte transformation tests are more commonly used to diagnose non-immediate reactions. In this review, we describe different in vitro techniques employed to diagnose antibiotic allergy.

Epidemiology, Mechanisms, and Diagnosis of Drug-Induced Anaphylaxis

Anaphylaxis is an acute, life-threatening, multisystem syndrome resulting from the sudden release of mediators by mast cells and basophils. Although anaphylaxis is often under-communicated and thus underestimated, its incidence appears to have risen over recent decades. Drugs are among the most common triggers in adults, being analgesics and antibiotics the most common causal agents. Anaphylaxis can be caused by immunologic or non-immunologic mechanisms. Immunologic anaphylaxis can be mediated by IgE-dependent or -independent pathways. The former involves activation of Th2 cells and the cross-linking of two or more specific IgE (sIgE) antibodies on the surface of mast cells or basophils. The IgE-independent mechanism can be mediated by IgG, involving the release of platelet-activating factor, and/or complement activation. Non-immunological anaphylaxis can occur through the direct stimulation of mast cell degranulation by some drugs, inducing histamine release and leading to anaphylactic symptoms. Work-up of a suspected drug-induced anaphylaxis should include clinical history; however, this can be unreliable, and skin tests should also be used if available and validated. Drug provocation testing is not recommended due to the risk of inducing a harmful reaction. In vitro testing can help to confirm anaphylaxis by analyzing the release of mediators such as tryptase or histamine by mast cells. When immunologic mechanisms are suspected, serum-sIgE quantification or the use of the basophil activation test can help confirm the culprit drug. In this review, we will discuss multiple aspects of drug-induced anaphylaxis, including epidemiology, mechanisms, and diagnosis.

Evolution of diagnostic approaches in betalactam hypersensitivity

INTRODUCTION

Betalactams are the most widely used drugs against infections and the primary cause of antibiotic hypersensitivity reactions. Reaction patterns for different betalactams have been changing in accordance with consumption trends, and vary among countries. As a consequence, in vivo and in vitro tests have had to change with to keep up with new tendencies. Areas covered: This review is focused on advances in betalactam hypersensitivity diagnosis. Changes in in vivo methods have been limited to the inclusion of new haptens. In contrast, major progress has been achieved for in vitro tests since the 1960s, from the first description of immunoassays, the basophil activation test and the lymphocyte transformation test, to the more sophisticated assays developed in last years. Expert commentary: Issues with diagnosis are related to test sensitivity. In vivo tests show higher sensitivity, however they can be risky, especially in severe and life-threatening reactions. Therefore, we believe that in vitro tests should be the preferred method. Current efforts are under way to enhance their sensitivity. Only multidisciplinary approaches involving immunology, proteomics, nanotechnology and chemistry can help us to fully understand conjugate structures and mechanisms involved in hypersensitivity reactions to betalactams, and consequently lead to advances in in vitro methods.

The effects of distraction on symptoms during drug provocation test

Background

Some patients may have psychosomatic complaints due to their previous experiences during the drug hypersensitivity reaction. Worry about being hurt due to an administered drug is termed nocebo effect, which is the opposite of the placebo effect. In our study, we investigated the effect of distraction on symptoms during drug provocation test.

Methods

Our study included 112 patients who underwent DPTs for alternative purposes in our clinic. Previous hypersensitivity reactions of all the patients had objective signs. Patients were divided into two groups for the DPT. Sixty-three patients were kept busy during the test, performing tasks such as filling questionnaires, arranging files in alphabetical and numerical order, and doing archiving (Group 1). Forty-nine patients did not perform any tasks during the test (Group 2). Reactions that occurred during the test were recorded.

Results

During the DPT, 5 patients in Group 1 (5/63, 7.9%) and 17 patients in Group 2 (17/49, 34.7%), i.e. a total of 22 patients (22/112, 19.6%), had a reaction. There was a statistically significant difference between Group 1 and Group 2 according to the frequency of the reaction development.

Conclusions

Patient psychosomatic complaints during DPTs are proportional to their association with previous allergic reactions. In order to prevent such reactions, it may be beneficial to keep the patients busy with an activity in order to distract them during the test.

Penicillin allergy-getting the label right

Penicillinⁱ allergy is a potentially serious adverse reaction that impacts on antibacterial treatment options. Although it is commonly reported and recorded in medical records, only a minority of patients with a label of penicillin allergy actually have the condition confirmed. The term 'allergy' may be incorrectly applied to adverse reactions that do not have an immunological basis and inappropriate labelling of penicillin allergy can lead to the unnecessary avoidance of penicillins and other beta-lactam antibacterials. Here, we discuss key features that help to distinguish patients at low or high risk of having a true penicillin allergy, summarise what is known about the risk of allergic reactions to other beta-lactam antibacterials in patients with penicillin allergy and discuss the steps to consider when assessing a label of penicillin allergy.

Performance in real life of the European Network on Drug Allergy algorithm in immediate reactions to beta-lactam antibiotics

European Network on Drug Allergy (ENDA) has proposed an algorithm for diagnosing immediate beta-lactam (BL) allergy. We evaluated its performance in real life. During 1994-2014, 1779 patients with suspected immediate reactions to BL were evaluated following ENDA's short diagnostic algorithm. Five hundred and nine patients (28.6%) were diagnosed of BL hypersensitivity. Of them, 457 (25.7%) were at first evaluation [403 by skin tests (ST), 12 by positive IgE and 42 by controlled provocation tests (CPT)]. At second evaluation (SE), 52 additional patients (10.2% of allergic patients) were diagnosed, [50 (2.8%) by ST and 2 (0.1%) by CPT]. Time between reaction and study was significantly longer in patients diagnosed at SE (median 5 vs 42 months; IQR 34 vs 170; P < 0.0001). Anaphylaxis was significantly associated with a diagnosis at SE. European Network on Drug Allergy/EAACI protocol was appropriate and safe when evaluating BL immediate reactions. Re-evaluation should be performed, particularly when anaphylaxis and long interval to diagnosis are present.

Return to sender: the need to re-address patient antibiotic allergy labels in Australia and New Zealand

BACKGROUND/AIM

Antibiotic allergies are frequently reported and have significant impacts upon appropriate prescribing and clinical outcomes. We surveyed infectious diseases physicians, allergists, clinical immunologists and hospital pharmacists to evaluate antibiotic allergy knowledge and service delivery in Australia and New Zealand.

METHODS

An online multi-choice questionnaire was developed and endorsed by representatives of the Australasian Society of Clinical Immunology and Allergy (ASCIA) and the Australasian Society of Infectious Diseases (ASID). The 37-item survey was distributed in April 2015 to members of ASCIA, ASID, the Society of Hospital Pharmacists of Australia and the Royal Australasian College of Physicians.

RESULTS

Of 277 respondents, 94% currently use or would utilise antibiotic allergy testing (AAT) and reported seeing up to 10 patients/week labelled as antibiotic-allergic. Forty-two per cent were not aware of or did not have AAT available. Most felt that AAT would aid antibiotic selection, antibiotic appropriateness and antimicrobial stewardship (79, 69 and 61% respectively). Patients with the histories of immediate hypersensitivity were more likely to be referred than those with delayed hypersensitivities (76 vs 41%, P = 0.0001). Lack of specialist physicians (20%) and personal experience (17%) were barriers to service delivery. A multidisciplinary approach was a preferred AAT model (53%). Knowledge gaps were identified, with the majority overestimating rates of penicillin/cephalosporin (78%), penicillin/carbapenem (57%) and penicillin/monobactam (39%) cross-reactivity.

CONCLUSIONS

A high burden of antibiotic allergy labelling and demand for AAT is complicated by a relative lack availability or awareness of AAT services in Australia and New Zealand. Antibiotic allergy education and deployment of AAT, accessible to community and hospital-based clinicians, may improve clinical decisions and reduce antibiotic allergy impacts. A collaborative approach involving infectious diseases physicians, pharmacists and allergists/immunologists is required.

The influence of the carrier molecule on amoxicillin recognition by specific IgE in patients with immediate hypersensitivity reactions to betalactams

The optimal recognition of penicillin determinants, including amoxicillin (AX), by specific IgE antibodies is widely believed to require covalent binding to a carrier molecule. The nature of the carrier and its contribution to the antigenic determinant is not well known. Here we aimed to evaluate the specific-IgE recognition of different AX-derived structures. We studied patients with immediate hypersensitivity reactions to AX, classified as selective or cross-reactors to penicillins. Competitive immunoassays were performed using AX itself, amoxicilloic acid, AX bound to butylamine (AXO-BA) or to human serum albumin (AXO-HSA) in the fluid phase, as inhibitors, and amoxicilloyl-poli-L-lysine (AXO-PLL) in the solid-phase. Two distinct patterns of AX recognition by IgE were found: Group A showed a higher recognition of AX itself and AX-modified components of low molecular weights, whilst Group B showed similar recognition of both unconjugated and conjugated AX. Amoxicilloic acid was poorly recognized in both groups, which reinforces the need for AX conjugation to a carrier for optimal recognition. Remarkably, IgE recognition in Group A (selective responders to AX) is influenced by the mode of binding and/or the nature of the carrier; whereas IgE in Group B (cross-responders to penicillins) recognizes AX independently of the nature of the carrier.