Skin testing and drug provocation in the diagnosis of nonimmediate reactions to aminopenicillins in children

The safety of initial single therapeutic dose challenge with a 5-day prolonged drug provocation test in children with a history of low-risk non-immediate reactions to beta-lactam antibiotics

Background: Although the gold standard for diagnosing beta-lactam antibiotic (BLA) allergy is the drug provocation test (DPT), there is no standardized protocol for children. Objective: We aimed to evaluate the clinical features and DPT results of children with a history of low-risk non-immediate reactions (NIR) to BLA who underwent initial direct single therapeutic dose challenge with a 5-day prolonged DPT. Methods: We retrospectively evaluated children ages 0-18 years with a history of low-risk NIRs to BLAs. On the first day of provocation, a single-dose DPT protocol without any skin test was administered at the clinic. The therapeutic dose was adjusted to not exceed the maximum single-unit dose (MSUD) for age and weight. The DPT protocol was administered with 100% of MSUD. To identify children with delayed reactions, the parents or caregivers were told to continue giving the medication at home for 5 days. Results: One hundred and nine children were included in this study. The median (interquartile range) age of the children was 62.5 months (26.5-94 months). Of the suspected drugs, the main culprit drug was amoxicillin-clavulanic acid for 89 children (81.7%). The most common clinical manifestation was maculopapular exanthema, which occurred in 85 children (78%), and 8 (7.3%) had a positive DPT result. Three children (2.8%) developed a reaction after the first DPT dose. The remaining children continued to use the suspected BLA at home. Five children (4.7%) developed a reaction while using the drug at home. All the children with positive DPT results developed mild cutaneous signs and presented with a reaction to amoxicillin-clavulanic acid. None had a systemic or severe cutaneous reaction. Conclusion: Initial direct single therapeutic dose challenge with a 5-day prolonged DPT is a useful and safe way to assess low-risk NIRs to BLAs in children.

Challenging dogmas: Intravenous versus oral beta-lactam antibiotic provocation tests

Background

Drug provocation tests (DPT) are considered the gold standard procedure to ascertain the diagnosis of beta-lactam (BL) allergy. Regarding route of administration, current recommendations prioritize oral challenges, considering them safer, and reserving the intravenous route for drugs for which this is the only formulation.

Objective

To compare in terms of tolerance and safety two protocols of BL DPT, using an oral protocol (OR-DPT) and an intravenous protocol (IV-DPT).

Methods

A descriptive, retrospective study was performed, including adult patients who underwent IV-DPT or OR-DPT for suspected immediate or delayed hypersensitivity to BL antibiotics, over a period of 4 years (between January 2018 and December 2021). Demographical data, index hypersensivity reactions' characteristics and tolerance to DPT were reviewed.

Results

A total of 1036 patients underwent DPT, mean age of 56.8 (standard deviation, SD, 17.8) years, 655 were women (63.2%). Immediate drug hypersensitivity reactions (DHR) had occurred in 564 of patients (54.4%). OR-DPT were performed in 439 (42.4%) and IV-DPT in 597 (57.6%). The frequency of reactions during DPT, regardless of the route used, was low (3.6%): only 16 (3.6%) in OR-DPT and 21 (3.5%) in IV-DPT. From IV-DPT, 16 out 21 DHR during DPT were immediate compared with 4 out of 16 in OR-DPT. Adjusted relative risk of developing a hypersensitivity reaction during IV-DPT versus OR-DPT was 1.13 (95% confidence interval (CI)0.57-2.22).

Conclusion

The results suggest that OR-DPT and IV-DPT are both safe procedures when adequately performed. However, IV-DPT protocols showed a higher rate of immediate DHR during DPT probably due to the selection of basal high-risk patients to undergo IV-DPT. In conclusion, IV-DPT may be considered as an option for challenges in drug-allergy studies, entailing a precise administration.

Beta-lactam hypersensitivity in children: Frequency and risk factors

AIMS

To determine the frequency of an authentic β-lactam (BL) hypersensitivity (HS) amongst a large number of children and to identify clinical risk factors that predict this hypersensitivity.

METHODS

All children with suspected BL allergy were evaluated by skin tests (ST) with the suspected BL. A 1-day oral provocation test (OPT) was performed in children with negative ST. We defined an authentic BL-HS case if the child exhibited a positive ST or a positive OPT. Risk factors associated with BL-HS were assessed using a univariate analysis. Covariates showing a P-value <.2 were included in the multivariate logistic regression analysis to determine independent predictors.

RESULTS

A total of 354 patients reporting 368 suspected BL reactions were included. The diagnosis of BL-HS was established in 24 children (6.7%). All these children had a positive ST. OPT was performed in 30 patients and was negative in all of them. In 110 children with a negative ST, BL was tolerated. In the risk factors analysis, 164 children were included. Older age (>5 years) at the reaction (odds ratio = 1.11; 95% confidence interval, 1.01-1.22; P = .02) and BL administered (odds ratio = 7.7; 95% confidence interval, 2.76-21.8; P < .001) were significantly associated with authentic BL-HS.

CONCLUSION

BL-HS should be evaluated with an appropriate allergy work-up before strict prohibition is made. In addition, age of patient and BL involved can be used as predictive factors of developing BL-HS in this population.

Simplifying the drug provocation test in non-immediate hypersensitivity reactions to amoxicillin in children: The experience of a tertiary care allergy unit

BACKGROUND

Mild non-immediate reactions (NIR) to beta-lactams (βLs) are the most common manifestation of adverse drug reactions in children, and the drug provocation test (DPT) remains the gold standard for diagnosis. However, there are still controversies about the protocol that should be used, especially regarding the administration of doses and the DPT length.

OBJECTIVE

This study aimed to evaluate a pediatric population with a history of mild NIR to amoxicillin (AMX) or to amoxicillin-clavulanic acid (AMX/CL) who underwent a diagnostic workup including a DPT with the culprit drug, to understand if a graded DPT or, instead, a single full dose could be the most appropriate way of administration in clinical practice.

METHODS

The data of children were retrospectively analyzed for a 5-year period, with demographic and clinical characteristics collected. We reported the allergy workup and the results of the DPT performed with the administration of incremental doses and a prolonged DPT at home for a total of 5 days.

RESULTS

Three hundred fifty-four patients were included. Overall, 23/354 (6.5%) DPTs were positive: 11/23 patients showed a reaction after 2-8 h after the last dose on the 1st or 2nd day (1 reacted 30 min after the last dose), 1/23 reacted with urticaria 30 min after the first dose, 11/23 reacted at home on the 5th day of the DPT.

CONCLUSION

This paper indirectly suggests that a single therapeutic dose administered on the 1st day of a DPT could be safe in the diagnostic workup of mild NIR to AMX/CL. Moreover, this could be less time-consuming as patients would spend less time in the hospital, also considering the public health restrictions imposed during the COVID-19 pandemic.

Drug Allergy Delabeling Programs: Recent Strategies and Targeted Populations

Drug allergy delabeling programs have become an essential element of antibiotic stewardship. Development of delabeling programs involves careful selection of target patient population, thoughtful design of delabeling approach, stakeholder engagement, assembly of key team members, implementation, and evaluation of clinical and safety outcomes. Recent programs have targeted patients thought to be most likely to benefit from removal of inaccurate antibiotic allergy labels, those with β-lactam antibiotic allergies and high-risk populations likely to need β-lactam antibiotics as first-line treatment. This review provides an overview of current risk stratification methods and β-lactam cross-reactivity data and summarizes how different inpatient and outpatient delabeling programs have used these concepts in delabeling algorithms. β-Lactam delabeling programs for inpatients, pediatric patients, and programs utilizing telehealth have been implemented with good outcomes. This review also focuses on delabeling programs for high-risk populations likely to benefit from first-line β-lactam antibiotics. These populations include perioperative, prenatal, and immunocompromised patients. Delabeling programs have been successful in the inpatient and outpatient settings at enabling appropriate antibiotic use. This article reviews delabeling strategies utilized by these programs with a focus on highlighting elements key to their success and future areas for innovation.

Diagnosis of non-immediate hypersensitivity to amoxicillin in children by skin test and drug provocation tests: A retrospective case-series study

BACKGROUND

Skin rash often occurs upon oral administration of amoxicillin in children, due to non-immediate hypersensitivity. However, information on delayed hypersensitivity to amoxicillin is scarce. Moreover, the appropriate diagnostic method and actual diagnostic rate of delayed hypersensitivity to amoxicillin among Japanese children are unclear. We conducted intradermal tests (IDTs) and drug provocation tests (DPTs) and retrospectively investigated the proportion of children with a definitive diagnosis of non-immediate hypersensitivity to amoxicillin. We then evaluated the characteristics of patients with a positive allergic workup.

METHODS

We enrolled children referred for suspected findings of mild or moderate non-immediate hypersensitivity to amoxicillin between August 2018 and March 2020. If the IDT in the delayed phase was negative, DPT with amoxicillin (60-90 mg/kg/day) was performed for 7 days. Non-immediate hypersensitivity to amoxicillin was defined when IDT or DPT was positive. We evaluated the potential of the drug-induced lymphocyte stimulation test (DLST) to reveal hypersensitivity to amoxicillin.

RESULTS

This study enrolled 27 children. Fourteen children (52%) had hypersensitivity to amoxicillin, of whom 12 had positive IDTs and two had positive DPTs. No differences in age, sex, history of allergic disease, days from oral use to symptom onset, type of rash at symptom onset, generalized rash, and DLST results were observed between the hypersensitivity and non-hypersensitivity groups.

CONCLUSIONS

Examination should be performed for children with mild or moderate reactions because positive cases have no significant features and half of the suspected cases are negative.

Patterns of response and drugs involved in hypersensitivity reactions to beta-lactams in children

BACKGROUND

Beta-lactams generate different allergenic determinants that induce selective or cross-reactive drug hypersensitivity reactions (DHRs). We aimed to identify the drugs involved, the selectivity of the response, the mechanism, and the value of the different diagnostic tests for establishing a diagnosis in children evaluated for DHRs to beta-lactams.

METHODS

Prospective study evaluating children aged under 16 years reporting DHRs to beta-lactams. Reactions were classified as immediate and non-immediate reactions. The workup included sIgE, skin testing, and drug provocation tests (DPTs) for immediate reactions and patch testing and DPTs for non-immediate ones.

RESULTS

Of the 510 children included, 133 were evaluated for immediate reactions and confirmed in 8.3%. Skin test/in vitro IgE contributed to diagnosing half of the cases. Selective reactions occurred with amoxicillin (63%), followed by common penicillin determinants (27%) and cephalosporins (0.9%). Among non-immediate reactions (11.4% of the 377 children evaluated), most required DPTs, 52.7% of which were positive at 6-7 days of drug challenge. Selective reactions were identified with amoxicillin (80%), penicillin G (7.5%), cephalosporins (7.5%), and clavulanic acid (5%). Urticaria and maculopapular exanthema were the most frequent entities.

CONCLUSIONS

There were few confirmed cases of either type of reaction. Skin testing proved less valuable in non-immediate reactions, over half of which would also have been lost in a short DPT protocol. Selective responders to amoxicillin were more likely to have non-immediate reactions, while clavulanic acid selectivity was exclusive to the non-immediate typology. Over half the cases with DPTs required 6-7 days of treatment for DHR confirmation.

Pediatric Drug Allergies: Updates on Beta-Lactam, Nonsteroidal Anti-Inflammatory Drug, and Chemotherapeutic Reactions

Adverse drug reactions are frequently reported in pediatric patients. In this review article, the authors discuss pediatric drug allergies with emphasis on the most common culprits, beta-lactam antibiotics and non-steroidal anti-inflammatory drugs. The authors also discuss reactions to non-beta-lactam antibiotics and chemotherapeutics. Skin testing has not yet been validated for many drugs, although notable exceptions include penicillin and carboplatin. The gold standard for diagnosis in most cases remains drug challenge, and the need for penicillin skin testing prior to oral provocation challenge has been questioned in recent studies. Successful desensitizations have also been reported with several drugs.

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.

Single-dose prolonged drug provocation test, without previous skin testing, is safe for diagnosing children with mild non-immediate reactions to beta-lactams

INTRODUCTION

Mild non-immediate reactions (NIRs) to beta-lactams (BLs) are the most frequent manifestation of drug allergy in children. The diagnostic approach is complex as the utility of skin tests (STs) and lymphocyte transformation tests (LTTs) is controversial. Drug provocation test (DPT) is the gold standard, although no standardized protocols exist. We aimed to investigate the utility of DPT in a unique dose without previous STs, and LTTs in the diagnosis of NIRs to BLs in children.

METHODS

We prospectively evaluated children 0-14 years old referred to the Regional University Hospital of Málaga during 2017-2020 reporting NIRs to BLs. We performed a DPT with a unique dose followed by regular treatment at home. If positive, STs and LTTs were done after the reaction had disappeared.

RESULTS

We included 194 children, having 24 (12.4%) a positive DPT. The main culprit was AX (70.1%) followed by AX-clavulanic acid (CLV) (26.8%) and the main symptoms maculopapular exanthema (MPE) (49.5%) and delayed-urticaria (48.5%). A decrease (p = 0.013) in the interval of days between drug administration and onset of symptoms was observed in positive DPT compared with the original reaction (3.5 vs 6 days), with no differences in the overall percentage of MPE and delayed-appearing urticaria (p = 0.551). No severe reactions occurred during DPT. Moreover, STs were positive in 13.33% and LTTs in 52.9%.

CONCLUSIONS

Single-dose DPT without previous STs is a safe and useful way to assess NIRs to BLs in children. LTT has shown to be useful, confirming a T-cell mechanism involved in these reactions.

Delabeling Delayed Drug Hypersensitivity: How Far Can You Safely Go?

Delayed immune-mediated adverse drug reactions (IM-ADRs) are defined as reactions occurring more than 6 hours after dosing. They include heterogeneous clinical phenotypes that are typically T-cell-mediated reactions with distinct mechanisms across a wide spectrum of severity from benign exanthems through to life-threatening cutaneous or organ-specific diseases. For mild reactions such as benign exanthem, considerations for delabeling are similar to immediate reactions and may include a graded or single-dose drug challenge with or without preceding skin or patch testing. Evaluation of challenging cases such as the patient who is on multiple drugs at the time a severe delayed IM-ADR occurs should prioritize clinical ascertainment of the most likely phenotype and implicated drug(s). Although not widely available and validated, procedures such as patch testing, delayed intradermal skin testing, and laboratory-based functional drug assays or genetic (human leukocyte antigen) testing may provide valuable information to further help risk stratify patients and identify the likely implicated and/or cross-reactive drug(s). The decision to use a drug challenge as a diagnostic or delabeling tool in a patient with a severe delayed IM-ADR should weigh the risk-benefit ratio, balancing the severity and priority for the treatment of the underlying, and the availability of alternative efficacious and safe treatments.

Betalactam hypersensitivity: The importance of delabelling in primary care

PATIENTS AND METHODS

An allergy work-up was performed on adult patients with a history of a penicillin allergy seen by primary medical care in Monastir (Tunisia) between July 2016 and February 2018. Patients with negative skin tests were challenged with amoxicillin. Patients who were delabelled were contacted by phone after 6 months to determine outcomes after any therapeutic penicillin-class antibiotic intake.

RESULTS

A total of 39 patients were evaluated and 33 (84.6%) were delabelled. Five patients were penicillin skin-test positive and one was oral challenge positive. We succeeded in contacting 33 delabelled patients at 6 months. Twenty-two patients tolerated a subsequent therapeutic course of amoxicillin, eight patients did not retake penicillin due to a lack of therapeutic indication, and three patients refused an indicated penicillin use fearful of another reaction.

CONCLUSION

This study highlights the importance of allergy work-up in the diagnosis of beta-lactam hypersensitivity. Most patients were excessively labelled as beta-lactam allergic and this mislabelling could increase healthcare costs and lead to the development of drug resistance by the use of wide-spectrum antibiotics.

Drug Provocation Tests for Assessing Antibiotic Hypersensitivity: Is Shorter Also Better?

BACKGROUND

Suspected antibiotic hypersensitivity in children is a frequent reason for consultation. Skin test performance and drug provocation test (DPT) duration are controversial issues. The objective of this study was to assess the effectiveness of diagnostic tests used in the study of antibiotic hypersensitivity and to estimate an optimal duration for DPT.

METHODS

Sixty-two children with a suspected hypersensitivity reaction to antibiotics were studied. Skin tests were performed on all patients. In the case of negative results, DPTs were performed for a duration similar to the time elapsed from the start of treatment until the onset of the reaction.

RESULTS

The frequency of antibiotic hypersensitivity in the study population was 8.1% (5 of 62). Only 1 patient showed positive skin tests. The other allergic patients were diagnosed by DPT, which reproduced the reaction within the first 6 hours in all but one of them.

CONCLUSIONS

Shortening DPT duration may decrease the sensitivity of the test for the diagnosis of non-IgE-mediated hypersensitivity; however, it should be considered as an opportunity to reduce the resulting microbial resistances.

Allergy to beta-lactam antibiotics in children: Risk factors for a positive diagnostic work-up

BACKGROUND

Allergy to beta-lactam (βL) antibiotics is highly reported in children, but rarely confirmed. Risk factors for a positive diagnostic work-up are scarce. The primary aim was to characterize the cases of children with confirmed βL allergy, investigating potential risk factors. Secondary aims were to assess the prevalence of allergy to βL in this population and to confirm the safety of less extensive diagnostic protocols for milder reactions.

METHODS

We reviewed the clinical data from all children evaluated in our Department for suspected βL allergy, over a six-year period.

RESULTS

Two hundred and twenty children (53% females) with a mean age of 6.5±4.2 years were evaluated. Cutaneous manifestations were the most frequently reported (96.9%), mainly maculopapular exanthema (MPE). The reactions were non-immediate in 59.5% of the cases. Only 23 children (10.5%) were diagnosed with allergy to βL. The likelihood of βL allergy was significantly higher in children with a family history of drug allergy (p<0.001) and in those with a smaller time period between the reaction and the study (p=0.046). The probability of not confirming βL allergy is greater in children reporting less severe reactions (p<0.001) and MPE (p<0.001). We found the less extensive diagnostic protocol in milder reactions safe, since only 4.2% of the children presented a positive provocation test (similar reaction as the index reaction).

CONCLUSION

This study highlights family history of drug allergy as a risk factor for a positive diagnostic work-up. Larger series are required, particularly genetic studies to accurately determine future risk for βL allergy in children.

Prospective study of 5-day challenge with penicillins in children

OBJECTIVES

To examine if a 5-day challenge with penicillin improves the diagnostic sensitivity compared with a single full dose in children with mild skin reactions.

DESIGN

Subjects referred with suspected allergy to penicillin were consecutively included. Irrespectively of the morphology of the index reaction and the result of specific IgE, all subjects underwent a two-step titrated drug provocation test (DPT) with the culprit drug followed by a 5-day challenge at home.

PARTICIPANTS

Children and adolescents aged 0-18 years referred to allergic workup for penicillin hypersensitivity at two paediatric Danish centres. Only subjects with non-severe skin reactions were included.

RESULTS

A total of 305 subjects were included and 22 (7%) of the DPTs were positive. Three subjects reacted within 1 hour of the first full dose and nine reacted 1-8 hours after the first full dose. Additional 10 positive reactions were observed during the prolonged provocation. Seven subjects reacted after the second full dose and three reacted after 3-6 days. Only mild skin rashes were observed. Eighteen subjects had a specific IgE to a penicillin >0.1 kU/L. Only one of these had a positive DPT.

CONCLUSION

In children, a DPT with penicillins should include at least two full doses. In children with mild hypersensitivity reactions it may be safe to perform DPTs despite a low specific IgE.

TRIAL REGISTRATION NUMBER

NCT04331522.

Allergological Study of 565 Elderly Patients Previously Labeled as Allergic to Penicillins

Purpose

Elderly people thought to have an allergy to beta-lactams (BLs) may tolerate the drugs in subsequent exposures due to initial false labeling of allergies, the spontaneous loss of sensitivity to BLs over time or age-related decline in sensitization. As a result, they may be treated with less appropriate antibiotics, causing more side effects and entailing increased costs for health systems. The aim of this investigation was to assess whether patients in the third and fourth age with previously confirmed allergies to BLs had lost sensitization and could tolerate these antibiotics.

Patients and methods

Patients allergic to BLs were divided into group A (aged 60-79 years) and B (aged ≥80 years). Clinical history, skin testing, drug challenge tests (DCT) and evaluation of resensitization were used to classify participants as showing immediate reactions, non-immediate reactions, or tolerance. We compared clinical entities, drugs involved, and final outcome by age group.

Results

Of 1362 cases evaluated, 565 underwent an allergological study. The skin was the most common organ involved. Anaphylaxis and side chain reactions were more frequent in group A (p<0.01), as were positive DCT. Classical benzylpenicillin determinants (benzylpenicilloyl and/or minor determinant mixture) were more frequent triggers in group B (p< 0.01). Resensitization after challenge occurred in very few participants.

Conclusion

The risk for allergy to BLs decreases with age and a history of anaphylaxis by BLs is a predictor of positive results in skin tests (ST). Both immunoglobin E (IgE) and T-cell-mediated responses can disappear in elderly people, who can develop tolerance to these antibiotics. These results are of clinical relevance to patients who need to be treated with antibiotics from this family.

Adverse Drug Reactions Across the Age Continuum: Epidemiology, Diagnostic Challenges, Prevention, and Treatments

Adverse drug reactions (ADRs) are common and important complications of drug therapy for children. The risk for ADRs changes over childhood, as do the nature and types of ADRs. Importantly, the risk and nature of ADRs in children are markedly different from those of adults, and adult data cannot be relied on to guide safe drug therapy in children. There are groups of children, notably those with complex and chronic diseases, who are at substantial risk for ADRs. The evaluation of an undesired effect during therapy is ideally accomplished by an organized approach that is a skill that clinicians who care for children-especially those children at high risk for ADRs must have. Additionally, clinicians as well as drug regulatory agencies and industry need to be both vigilant and astute as well as aware that ADRs in children are often different in nature and frequency from those in adults. The increasing use of pharmacogenomics to guide drug dosing and the increasing number of biological agents will provide new sets of challenges to clinicians over the next decade.

Pediatric Drug Allergies: Updates on Beta-Lactam, Nonsteroidal Anti-Inflammatory Drug, and Chemotherapeutic Reactions

Adverse drug reactions are frequently reported in pediatric patients. In this review article, the authors discuss pediatric drug allergies with emphasis on the most common culprits, beta-lactam antibiotics and non-steroidal anti-inflammatory drugs. The authors also discuss reactions to non-beta-lactam antibiotics and chemotherapeutics. Skin testing has not yet been validated for many drugs, although notable exceptions include penicillin and carboplatin. The gold standard for diagnosis in most cases remains drug challenge, and the need for penicillin skin testing prior to oral provocation challenge has been questioned in recent studies. Successful desensitizations have also been reported with several drugs.

Short and extended provocation tests have similar negative predictive value in non-immediate hypersensitivity to beta-lactams in children

INTRODUCTION AND OBJECTIVES

Drug provocation tests (DPTs) are the gold-standard method to diagnose non-immediate hypersensitivity reactions (NIHSR) to beta-lactam antibiotics (BL) in children. Our aim was to compare the negative predictive value (NPV) of one-day (short) DPT versus 3-7 days (extended) DPT for the diagnosis of NIHSR to BL in paediatric age. A secondary aim was to compare confidence on drug re-exposure after short and extended negative DPTs.

METHODS

The occurrence of HSR on drug re-exposure and drug refusal after negative diagnostic DPTs were evaluated in children/adolescents with a history of NIHSR to BL using a questionnaire performed six months to ten years after DPT. Patients were divided into two groups according to the protocol performed: short DPT vs. extended DPT.

RESULTS

We enrolled 212 children and adolescents (86 females, 126 males, mean age at DPT 5.52 years, p25=3 years, p75=7.25 years): 69 tested with short DPT, and 143 with extended DPT. The NPV of both types of DPT together was 95.2%. The NPV of short DPT was 97.5% and the NPV of extended DPT was 93.8% (p=0.419). After negative DPT, beta-lactams were refused by carers in 14.75% of the children requiring subsequent treatment, 6.98% in the short DPT group and 18.99% in the extended DPT group (p=0.074).

CONCLUSIONS

In our paediatric sample, prolonging drug administration did not increase the NPV of diagnostic DPT for NIHSR to BL or reduce drug refusal. Altogether, the data here reported suggest that, however intuitive, prolonging DPT is not beneficial in the parameters analysed.

The Limited Value of Prolonged Drug Challenges in Nonimmediate Amoxicillin (Clavulanic Acid) Hypersensitivity

BACKGROUND

Misdiagnosis of amoxicillin (clavulanic acid) (AX(/CL)) hypersensitivity has serious consequences. A drug challenge (DC) is the final diagnostic to affirm or infirm AX(/CL) hypersensitivity. However, uncertainties remain whether a prolonged drug challenge (pDC) should benefit the diagnosis of a nonimmediate AX(/CL) hypersensitivity.

OBJECTIVE

To assess the added value of a standardized 7-day pDC in the diagnosis of nonimmediate or unclear penicillin hypersensitivity.

METHODS

A total of 132 patients with a history of a nonimmediate hypersensitivity reaction or an unclear reaction to AX(/CL) or an undefined penicillin with a negative diagnostic workup including a single-day DC (DC) with AX(/CL) were selected. In all these patients, an additional pDC with AX(/CL) was planned. Thirteen patients started the pDC immediately after the DC. To ensure that hypersensitivity symptoms manifesting during the pDC course do not result from the DC, in the remaining 119 patients, the pDC was scheduled after a washout of 1 week.

RESULTS

A total of 128 patients (12 without washout, 116 with washout) completed the pDC. Three patients reacted with a mild maculopapular exanthema. However, the value of a pDC was evidenced in only 1 patient who reacted during her pDC after an uneventful washout. In 2 patients pDC was cancelled because they reacted during the washout.

CONCLUSIONS

A pDC is of limited added value to the diagnostic algorithms of nonimmediate hypersensitivity reaction or unclear hypersensitivity reactions to AX(/CL). In our hands, the traditionally recommended diagnostic algorithm that offers a 1-day DC as a final diagnostic in patients with negative workup for AX(/CL) is appropriate.

SIAIP position paper: provocation challenge to antibiotics and non-steroidal anti-inflammatory drugs in children

Drug hypersensitivity reactions (DHRs) in childhood are mainly caused by betalactam or non-betalactam antibiotics, and non-steroidal anti-inflammatory drugs (NSAIDs). Laboratory tests for identifying children who are allergic to drugs have low diagnostic accuracy and predictive value. The gold standard to diagnose DHR is represented by the drug provocation test (DPT), that aims of ascertaining the causative role of an allergen and evaluating the tolerance to the suspected drug. Different protocols through the administration of divided increasing doses have been postulated according to the type of drug and the onset of the reaction (immediate or non immediate reactions). DPT protocols differ in doses and time interval between doses. In this position paper, the Italian Pediatric Society for Allergy and Immunology provides a practical guide for provocation test to antibiotics and NSAIDs in children and adolescents.

Provocation Tests in Nonimmediate Hypersensitivity Reactions to β-Lactam Antibiotics in Children: Are Extended Challenges Needed?

BACKGROUND

β-Lactam antibiotics are the most common trigger of reactions in children with most of them being nonimmediate (85.5%), but proven allergy after the allergological workup is between 7% and 10%. There is no agreement on how to perform the provocation tests in these types of hypersensitivity reactions.

OBJECTIVE

To determine whether or not repeated doses of the β-lactams are required to reproduce a nonimmediate reaction in children.

METHODS

This is a retrospective observational study. We included children under 14 years who were referred for a nonimmediate reaction to β-lactams. All patients underwent a 1-day hospital provocation and were kept under observation at home during the following days for at least the time elapsed between the first dose and the symptoms of the index reaction. If no reaction was triggered, the patient resumed the provocation at home with 2 daily therapeutic doses for an equal of interval time.

RESULTS

Ninety-seven patients were included in the study. A positive reaction was recorded in 14 of them (14.4%). The short hospital provocation triggered 3 immediate reactions and 8 delayed reactions. The home rechallenge developed 1 immediate reaction and 2 delayed reactions.

CONCLUSIONS

Nonimmediate reactions to β-lactams in children may be triggered with a 1-day provocation test. We suggest to perform a 1-day provocation test followed by an observational period of at least the time interval of the index reaction. If this challenge is negative, an extended home provocation could subsequently be carried out.

Enhancing antibiotic stewardship by tackling "spurious" penicillin allergy

Approximately 90-99% of patients with a label of penicillin allergy (PenA) are not allergic when comprehensively investigated. An inaccurate label of PenA has major public health implications-longer hospital stay, more frequent hospital admissions, greater use of fluoroquinolones, glycopeptides, cephalosporins and other expensive antibiotics resulting in significantly higher costs to the health service and predisposing to Clostridium difficile, methicillin-resistant Staphylococcus aureus infections and vancomycin-resistant enterococcus. We describe lessons learnt from recent studies regarding possible reasons contributing to an inaccurate label of PenA as well as propose a concerted multidisciplinary approach to address this important public health problem. Given the unmet need for allergy services in the UK and several other countries and knowledge gaps regarding PenA amongst healthcare professionals, we describe the potential role for a computerized clinical decision support system to enable non-specialists rapidly identify and de-label "low-risk" hospitalized patients with a label of PenA thereby obviating the need for allergy tests. This approach however needs rigorous evaluation for feasibility, safety, patient and physician acceptability, cost-effectiveness and its compatibility with information technology systems currently employed in the health service.

Efficacy and Safety of 5-Day Challenge for the Evaluation of Nonsevere Amoxicillin Allergy in Children

BACKGROUND

Penicillin allergy is the most frequent drug allergy, among which aminopenicillins are reputed for causing delayed rashes in children, particularly in the context of viral infections. Despite a negative allergy evaluation, a significant proportion of individuals continue to avoid penicillin antibiotics for fear of an allergic reaction.

OBJECTIVE

To evaluate the safety and efficacy of a 5-day challenge to amoxicillin and the proportion of subsequent use of amoxicillin.

METHODS

Pediatric patients with a history of a reaction to amoxicillin were prospectively recruited in the study. All patients were challenged, and those with negative immediate challenges underwent an ambulatory 5-day challenge to amoxicillin to rule out nonimmediate reactions. Patients were called 2 years after their initial allergy evaluation to assess subsequent amoxicillin use and tolerance.

RESULTS

One hundred thirty children with a history of amoxicillin allergy underwent a graded drug provocation test (DPT) to amoxicillin. Three patients had a positive immediate challenge, 3 had a positive nonimmediate challenge, and 2 were equivocal. Of the 122 patients with a negative challenge, 114 (93.4%) were reached 2 years after their initial allergy evaluation: 75 had used antibiotics since, of which only 1 (1.3%) had refused to reuse amoxicillin because of fear of an allergic reaction. Finally, the 5-day DPT resulted in a 24.1% decrease in future penicillin avoidance compared with classical single-dose graded DPT performed for 1 day in a historical cohort (P < .0001).

CONCLUSION

The 5-day challenge is a safe and effective way to rule out nonimmediate amoxicillin allergy, and it ensures better compliance with future penicillin use.

Non-immediate-reading skin tests and prolonged challenges in non-immediate hypersensitivity to beta-lactams in children

BACKGROUND

A minority of children reporting non-immediate reactions to beta-lactams (BLs) are allergic. Allergy workup usually includes late-reading (48-72 hours) skin tests (ST) and short (1-3 days) drug provocation tests (DPT), regardless of the chronology of the index reaction. The sensitivity of hyper-late-reading (≥6-7 days) ST and of prolonged DPT for the diagnosis of non-immediate hypersensitivity to BLs is yet to be determined.

OBJECTIVES

To establish the diagnostic values of late-reading ST and hyper-late-reading ST and of prolonged DPT in children reporting non-immediate reactions to BLs.

METHODS

Prospective assessment of children reporting non-immediate reactions to BLs with late- and additional hyper-late-reading intradermal (ID) and patch tests, and if negative, with prolonged DPT.

RESULTS

Five hundred and fifty children reporting reactions to a single or several BLs (674 suspected BLs) were included. Non-immediate hypersensitivity to BLs was diagnosed in 63 children (11.5%), reporting 66 reactions (9.8%), based on responses in ST (n = 17, 25.8%: 5 to ID, 8 to patch tests, and 4 to both tests), DPT (n = 43, 65.2%), and clinical history (n = 6, 9.1%), including 3/9 children with severe cutaneous adverse reactions. Skin test positivity was observed after the 6-7th day in 14/17 children, and DPT positivity after a median time of 3 days. No severe reaction was observed after ST or during prolonged DPT.

CONCLUSION

Additional hyper-late-reading of ST enhanced their positivity. However, their overall sensitivity remained weak, especially in non-severe cases. Prolonged DPT are safe and may improve the performance of DPT in the diagnosis of non-immediate hypersensitivity to BLs.

A clinical decision-making algorithm for penicillin allergy

BACKGROUND

About 10% of subjects report suspected penicillin allergy, but 85-90% of these patients are not truly allergic and could safely receive beta-lactam antibiotics Objective: To design and validate a clinical decision-making algorithm, based on anamnesis (chronology, severity, and duration of the suspected allergic reactions) and reaching a 100% sensitivity and negative predictive value, to assess allergy risk related to a penicillin prescription in general practise.

STUDY DESIGN AND METHODS

All patients were included prospectively and explorated based on ENDA/EAACI recommendations. Results of penicillin allergy work-up (gold standard) were compared with results of the algorithm.

RESULTS

Allergological work-up diagnosed penicillin hypersensitivity in 41/259 patients (15.8%) [95% CI: 11.5-20.3]. Three of these patients were diagnosed as having immediate-type hypersensitivity to penicillin, but had been misdiagnosed as low risk patients using the clinical algorithm. Thus, the sensitivity and negative predictive value of the algorithm were 92.7% [95% CI: 80.1-98.5] and 96.3% [95% CI: 89.6-99.2], respectively, and the probability that a patient with true penicillin allergy had been misclassified was 3.7% [95% CI: 0.8-10.4].

CONCLUSIONS

Although the risk of misclassification is low, we cannot recommend the use of this algorithm in general practice. However, the algorithm can be useful in emergency situations in hospital settings. Key messages True penicillin allergy is considerably lower than alleged penicillin allergy (15.8%; 41 of the 259 patients with suspected penicillin allergy). A clinical algorithm based on the patient's clinical history of the supposed allergic event to penicillin misclassified 3/41 (3.7%) truly allergic patients.

Pro and Contra: Provocation Tests in Drug Hypersensitivity

Drug provocation test (DPT) is the controlled administration of a drug to diagnose immune- or non-immune-mediated drug hypersensitivity and the last step for accurate recognition of drug hypersensitivity reactions when the previous diagnostic evaluations are negative or unavailable. A DPT is performed only if other conventional tests fail to yield conclusive results. In each clinical presentation, "to provoke or not to provoke" a patient should be decided after careful assessment of the risk-benefit ratio. Well-defined benefits of DPT include confirmative exclusion of diagnoses of drug hypersensitivity and provision of safe alternatives. However, disadvantages such as safety, difficulty in interpretations of results, lack of objective biomarkers, risks of resensitization, efficiency in daily practice, and lack of standardized protocols, are poorly debated. This review summarizes the current published research concerning DPT, with particular emphasis on the advantages and disadvantages of DPT in an evidence-based manner.

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.

Old dog begging for new tricks: current practices and future directions in the diagnosis of delayed antimicrobial hypersensitivity

PURPOSE OF REVIEW

Antimicrobials are a leading cause of severe T cell-mediated adverse drug reactions (ADRs). The purpose of this review is to address the current understanding of antimicrobial cross-reactivity and the ready availability of and evidence for in-vitro, in-vivo, and ex-vivo diagnostics for T cell-mediated ADRs.

RECENT FINDINGS

Recent literature has evaluated the efficacy of traditional antibiotic allergy management, including patch testing, skin prick testing, intradermal testing, and oral challenge. Although patch and intradermal testing are specific for the diagnosis of immune-mediated ADRs, they suffer from drug-specific limitations in sensitivity. The use of ex-vivo diagnostics, especially enzyme-linked immunospot, has been highlighted as a promising new approach to assigning causality. Knowledge of true rates of antimicrobial cross-reactivity aids empirical antibiotic choice in the setting of previous immune-mediated ADRs.

SUMMARY

In an era of increasing antimicrobial resistance and use of broad-spectrum antimicrobial therapy, ensuring patients are assigned the correct 'allergy label' is essential. Re-exposure to implicated antimicrobials, especially in the setting of severe adverse cutaneous reaction, is associated with significant morbidity and mortality. The process through which an antibiotic label gets assigned, acted on and maintained is still imprecise. Predicting T cell-mediated ADRs via personalized approaches, including human leukocyte antigen-typing, may pave future pathways to safer antimicrobial prescribing guidelines.

Allergy to antibiotics in children: an overestimated problem

Antibiotics are the most prescribed drugs for children, and a relevant number of prescriptions are associated with the emergence of adverse events. Allergic reactions are the most frequently reported adverse events, with an incidence of up to 10% of all prescriptions. However, literature analysis has shown that allergy to antibiotics is generally overdiagnosed in children because in most cases the diagnosis is based only on the clinical history without a full allergy work-up. Consequently, children are often improperly deprived of narrow-spectrum antibiotics because of a suspected allergy to these drugs. β-Lactams, mainly penicillins, are more frequently involved as a cause of allergy to antibiotics, although allergic problems are reported for most of the antibiotic classes. Accurate diagnosis is essential for a precise definition of determination of allergy to a given drug. Diagnosis has to be based on history, laboratory tests and, when possible, on in vitro and drug provocation tests. Unfortunately, the allergological work-up is well structured only for β-lactam antibiotics, whereas for non-β-lactams few studies are available, with very limited experience in children. The main aim of this paper is to discuss the real relevance of allergy to antibiotics in children in order to provide physicians with the knowledge needed to establish an appropriate diagnostic allergy work-up and to make better use of antibiotic therapy.

Non-immediate hypersensitivity reactions to beta-lactam antibiotics in children - our 10-year experience in allergy work-up

BACKGROUND

Non-immediate reactions to beta-lactam antibiotics (BL) occur more than one hour after drug administration, and the most common manifestations are maculopapular exanthemas and delayed-appearing urticaria and/or angioedema. Infections can lead to skin eruptions and mimic drug hypersensitivity reactions (DHR), if a drug is taken at the same time. The most of children are labeled as 'drug allergic' after considering only the clinical history.

OBJECTIVE

To diagnose/detect a hypersensitivity or an infection which mimic DHR in children with non-immediate reactions to BL METHODS: A prospective survey was conducted in a group of 1026 children with histories of non-immediate reactions to BL by performing patch tests, skin tests, and in case of negative results, drug provocation tests (DPTs). In 300 children, a study was performed to detect infections by viruses or Mycoplasma pneumoniae.

RESULTS

Urticaria and maculopapular exanthemas were the most reported non-immediate reactions. Only 76 (7.4%) of 1026 children had confirmed non-immediate hypersensitivity reactions to BL. Fifty-seven children had positive delayed-reading intradermal tests (18 of these with a positive patch test). Nineteen children had positive DPT. Sixty-six of 300 children had positive tests for viruses or Mycoplasma pneumoniae and 2 of them had a positive allergy work-up.

CONCLUSIONS

A diagnostic work-up should be performed in all children with non-immediate reactions to BL, to remove a false label of hypersensitivity. Even though only 57 (5.5%) of 1026 children displayed positive responses to delayed-reading intradermal tests to BL, such tests appear to be useful in order to reduce the risk for positive DPTs.

Drug hypersensitivity in children: report from the pediatric task force of the EAACI Drug Allergy Interest Group

When questioned, about 10% of the parents report suspected hypersensitivity to at least one drug in their children. However, only a few of these reactions can be confirmed as allergic after a diagnostic workup. There is still a lack of knowledge on drug hypersensitivity (DH) epidemiology, clinical spectrum, and appropriate diagnostic methods particularly in children. Meanwhile, the tools used for DH management in adults are applied also for children. Whereas this appears generally acceptable, some aspects of DH and management differ with age. Most reactions in children are still attributed to betalactams. Some manifestations, such as nonsteroidal anti-inflammatory drug-associated angioedema and serum sickness-like reactions, are more frequent among young patients as compared to adults. Risk factors such as viral infections are particularly frequent in children, making the diagnosis challenging. The practicability and validity of skin test and other diagnostic procedures need further assessment in children. This study presents an up-to-date review on epidemiology, clinical spectrum, diagnostic tools, and current management of DH in children. A new general algorithm for the study of these reactions in children is proposed. Data are presented focusing on reported differences between pediatric and adult patients, also identifying unmet needs to be addressed in further research.

Management of allergy to penicillins and other beta-lactams

The Standards of Care Committee of the British Society for Allergy and Clinical Immunology (BSACI) and an expert panel have prepared this guidance for the management of immediate and non-immediate allergic reactions to penicillins and other beta-lactams. The guideline is intended for UK specialists in both adult and paediatric allergy and for other clinicians practising allergy in secondary and tertiary care. The recommendations are evidence based, but where evidence is lacking, the panel reached consensus. During the development of the guideline, all BSACI members were consulted using a Web-based process and all comments carefully considered. Included in the guideline are epidemiology of allergic reactions to beta-lactams, molecular structure, formulations available in the UK and a description of known beta-lactam antigenic determinants. Sections on the value and limitations of clinical history, skin testing and laboratory investigations for both penicillins and cephalosporins are included. Cross-reactivity between penicillins and cephalosporins is discussed in detail. Recommendations on oral provocation and desensitization procedures have been made. Guidance for beta-lactam allergy in children is given in a separate section. An algorithm to help the clinician in the diagnosis of patients with a history of penicillin allergy has also been included.

The diagnosis and management of antibiotic allergy in children: Systematic review to inform a contemporary approach

BACKGROUND

Adverse drug reactions (ADRs) to antibiotics are commonly reported among children, with some representing genuine drug allergies. Accurate diagnostic tests are required. Drug provocation testing (DPT) is accepted as the gold standard investigation among children with suspected antibiotic allergy. We conducted this review to ascertain the strength of current evidence for using DPT as the first-line investigation for suspected antibiotic allergy among children.

METHODS

Medline was searched in June 2014 for publications investigating antibiotic allergy among children.

RESULTS

865 publications were retrieved and 76 studies selected. ADRs are most common among children of 0-4 years, however only some reveal drug allergies. The best evidence demonstrates that around 0.21% of general paediatric outpatients demonstrate positive antibiotic intradermal (ID) testing or DPTs, while 6.8% of children attending emergency departments for suspected β-lactam allergy may fulfil DPT reactions. Four studies used DPT-based protocols to investigate suspected antibiotic allergy, with two of these conducting ID testing and DPTs across all participants. β-lactam and clarithromycin ID testing had sensitivities of 66.7% and 75%, with positive predictive values of 36% and 33%, respectively, when compared with DPT data.

CONCLUSIONS

Our literature review found four (6%) publications that performed DPTs to subjects' index antibiotic across all participants. No rigorous evidence supports using skin prick, ID or in vitro diagnostic testing; indeed, the testing regimens, extracts and positivity criteria used are inconsistent. We recommend that suspected non-serious antibiotic allergy should be primarily investigated using DPT-based clinical protocols. Data examining their safety, acceptability and diagnostic performance are required.

Amoxicillin allergy in children: five-day drug provocation test in the diagnosis of nonimmediate reactions

BACKGROUND

The drug provocation test (DPT) is the gold standard to rule out drug hypersensitivity. There are standardized DPT protocols to diagnose immediate reactions to drugs, but not for nonimmediate reactions.

OBJECTIVE

The aim of this study was to show the sensitivity and specificity of an allergy work-up that included a 5-day DPT in children with histories of nonimmediate reactions to amoxicillin through focusing on a pediatric population with histories of immediate and nonimmediate reactions to amoxicillin.

METHODS

Two hundred consecutive patients with histories of amoxicillin reactions referred to the Allergy Unit of Anna Meyer Children's Hospital for suspected drug allergy from 2008 to 2011 underwent in vivo tests with the culprit drug according to European Academy of Allergy and Clinical Immunology guidelines. Moreover, most of those children, regardless of the skin tests results, were challenged with amoxicillin for a total of 5 days.

RESULTS

In 4 years, 200 patients were evaluated for a history of drug hypersensitivity to amoxicillin. The majority of patients (76%) had a history of mild nonimmediate reactions. All 200 patients underwent skin tests, and 9 of 200 tested positive. A total of 177 DPTs were performed with amoxicillin for 5 days in each child. Diagnosis of amoxicillin allergy was confirmed by a DPT in 17 patients (9.6%); 14/17 had history of nonimmediate reactions; 4/14 (26.6%) reacted on day 5.

CONCLUSION

According to our results, a long-term DPT protocol increases the sensitivity of the allergy work-up, and it should be recommended for patients with a history of amoxicillin nonimmediate reaction.

Negative predictive value of drug provocation tests in children

BACKGROUND

The negative predictive value of the drug provocation test is important for both the patient and the physician. However, in children, this predictive value is unresolved.

METHODS

The study included patients who had drug provocation test with a suspected drug and was diagnosed as 'not allergic to the drug'. Three months after allergy workup, the patients were contacted and asked for reexposure to the tested drug. Patients who have reported reactions during reexposure were reevaluated with skin tests and drug provocation.

RESULTS

During the study period, 217 provocations were performed to 203 patients. Of these, 163 patients (80.3%) with 175 negative drug provocation tests could be contacted. Ninety-one (52%) of the 175 cases reported to use the tested drug again, and 11 (12%) of these cases declared that they had a new reaction. Two of the eleven cases refused reevaluation. Nine cases were evaluated by drug allergy workup. Two of the nine cases were classified as allergic after retests. Collectively, the negative predictive value was 95.6% (87 of 91 cases) for all drug challenges.

CONCLUSIONS

The negative predictive value of the drug provocation test is abundant in children; however, negative drug provocation tests do not necessarily predict tolerance for the drug.

Confirmed penicillin allergy among patients receiving benzathine penicillin prophylaxis for acute rheumatic fever

BACKGROUND

Beta-lactam antibiotics are the most frequent drugs prescribed in children worldwide. Acute rheumatic fever (ARF) is the major cause of acquired heart disease among children and adolescents. Recurrences due to inadequate penicillin prophylaxis are responsible for chronic valvular lesions requiring surgery. The fear of a severe allergic reaction is the leading cause of discontinuing prophylaxis.

OBJECTIVE

In this study, we aimed to reveal the frequency of adverse events and real allergic reactions to benzathine penicillin among children who are followed in our paediatric cardiology clinic with a diagnosis of ARF.

MATERIALS METHODS

The children who were followed with a diagnosis of ARF between January 2005 and December 2011 were searched for a history of penicillin allergy. Patients with a positive history were evaluated in our paediatric allergy clinic. Skin tests and provocation tests were performed with parental consent.

RESULTS

In total 535 children with a diagnosis of ARF were analysed for the study. Median follow up period was 24 months (12-36) [median (%25-75)]. Eleven of our 535 (11/17.641 injection) ARF patients were suspected to have allergic reactions after 17.641 penicillin injections but only one (0.18%) was diagnosed to have penicillin allergy after detailed evaluation.

CONCLUSION

Our data suggest that the frequency of penicillin allergy is much lower than suspected among children on penicillin prophylaxis for ARF. Consequently, penicillin prophylaxis should not be given up without proper evaluation of drug allergy.