Drug provocation tests to betalactam antibiotics: experience in a paediatric setting

Direct oral challenge for immediate and non-immediate beta-lactam allergy in children: A real-world multicenter study

BACKGROUND

Allergy to beta-lactam antibiotics (BLA) is frequently suspected in children, but a drug provocation test (DPT) rules it out in over 90% of cases. Direct oral DPT (DODPT), without skin or other previous tests, is increasingly been used to delabel non-immediate BLA reactions. This real-world study aimed to assess the safety and effectiveness of DODPT in children with immediate and non-immediate reactions to BLAs.

METHODS

Ambispective registry study in children (<15 years), attended between 2016 and 2023 for suspected BLA allergy in 15 hospitals in Spain that routinely perform DODPT.

RESULTS

The study included 2133 patients with generally mild reactions (anaphylaxis 0.7%). Drug provocation test with the implicated BLA was performed in 2014 patients (94.4%): 1854 underwent DODPT (86.9%, including 172 patients with immediate reactions). One hundred forty-five (7.2%) had symptoms associated with DPT, although only four reactions were severe: two episodes of anaphylaxis and two of drug-induced enterocolitis syndrome, which resolved rapidly with treatment. Of the 141 patients with mild reactions in the first DPT, a second DPT was considered in 87 and performed in 57, with 52 tolerating it without symptoms. Finally, BLA allergy was ruled out in 90.9% of the sample, confirmed in 3.4%, and remained unverified, usually due to loss to follow-up, in 5.8%.

CONCLUSIONS

Direct oral DPT is a safe, effective procedure even in immediate mild reactions to BLA. Many reactions observed in DPT are doubtful and require confirmation. Severe reactions are exceptional and amenable to treatment. Direct oral DPT can be considered for BLA allergy delabeling in pediatric primary care.

The Safety of the Direct Drug Provocation Test in Beta-Lactam Hypersensitivity in Children: A Systematic Review and Meta-Analysis

BACKGROUND

Direct drug provocation test (DPT) without prior skin testing (ST) has been investigated in children suspected of being at risk for beta-lactam (BL) hypersensitivity reaction (HSR). However, no systematic review and meta-analysis has investigated the efficacy and safety of direct DPT for BL-HSR in children.

OBJECTIVE

To investigate the prevalence of BL-HSR by direct DPT and the safety of direct DPT in children.

METHODS

We searched MEDLINE, EMBASE, Web of Science, and CINAHL from their inception to July 23, 2022, for studies that performed direct DPT in children with suspected BL-HSR, or for studies that performed DPT in all cases with ST results, but they ignored the ST results. The true prevalence was defined as the proportion of children who experienced an HSR during direct DPT. Safety was determined according to the proportion of children who developed a dangerous reaction following DPT.

RESULTS

Twenty-eight studies with 8,334 direct challenges were included. Fifteen studies included patients who presented with either immediate or nonimmediate HSR, and the majority of the index reactions were nonsevere. Amoxicillin/amoxicillin-clavulanic acid was the most commonly used during the DPT. The pooled prevalence of confirmed BL-HSR was 5.23% (95% CI 4.17-6.39; I² = 72%). Immediate and nonimmediate HSR were reported in 0.8% (95% CI 0.43-1.25; I² = 55.1%) and 3.69% (95% CI 2.66-4.87; I² = 79.77%), respectively. Severe reactions were found in 3 cases with the frequency of 0.036% (95% CI 0.012-0.112; I² = 0%).

CONCLUSIONS

The prevalence of BL-HSR by direct DPT was 5.23%, and the frequency of severe reactions from direct DPT was very low (0.036%). Our findings support direct DPT as a safe and effective delabeling tool in children with suspected nonsevere BL-HSR.

Allergic disorders and their risk factors in primary Sjögren's syndrome

Objective

This study aimed to evaluate the prevalence of allergic disorders in patients with primary Sjögren's syndrome (pSS), compare it with that of patients with rheumatoid arthritis (RA), and examine the risk factors in patients with pSS.

Methods

We retrospectively examined the records of patients diagnosed with pSS and RA who regularly visited our department between 2010 and 2020. Allergic disorders included drug allergy, food allergy, allergic contact dermatitis (ACD), allergic rhinitis (AR)/allergic conjunctivitis (AC), and asthma.

Results

Patients with pSS (292 patients) had a higher prevalence of food allergy, drug allergy, and AR/AC than those with RA (413 patients). The multivariate analysis revealed that patients with pSS who had drug allergy had a higher prevalence of food allergy, higher eosinophil levels, and higher positivity rates of anti-SS-related antigen A (SSA) antibodies than those without drug allergy; those with food allergy had a higher rate of ACD than those without food allergy and vice versa; those with AR/AC had a higher rate of ACD and asthma and higher eosinophil levels than those without AR/AC; those with asthma had a higher rate of AR/AC than those without asthma.

Conclusions

Patients with pSS had a higher prevalence of allergic disorders than those with RA. Among patients with pSS, the risk factors for drug allergy were food allergy, higher eosinophil levels, and positivity for anti-SSA antibodies, the risk factor for food allergy was ACD and vice versa, the risk factors for AR/AC were ACD, asthma, and high eosinophil levels, and the risk factor for asthma was AR/AC.

New diagnostıc perspectives in the management of pediatrıc beta-lactam allergy

Since overdiagnosis of beta-lactam (BL) allergy is common in the pediatric population, delabeling is a critical part of antimicrobial stewardship. Undesirable consequences of inaccurate BL allergy labeling can be handled by incorporating traditional delabeling or newer risk-based strategies into antibiotic stewardship programs. Conventional assessment of BL allergy relies upon a stepwise algorithm including a clinical history with skin testing followed by drug provocation tests (DPTs). However, a growing number of studies highlighted the suboptimal diagnostic value of skin testing in children. Recently, there has been a paradigm shift in the practice of BL allergy assessment due to recent challenging data which emphasize the safety and accuracy of direct DPTs in children with a suspicion of non-immediate mild cutaneous reactions such as maculopapular eruption, delayed urticaria, and possibly also for benign immediate reactions such as urticaria/angioedema. Identifying low-risk BL allergy patients, in whom skin tests can be skipped and proceeding directly to DPTs could be safe, has become a hot topic in recent years. New risk stratification and predictive modeling studies that have the potential to better predict BL allergy risk status have recently been introduced into the field of drug allergy, particularly in adults. However, in contrast to adults, risk assessment studies in children are rare, and optimal risk definitions are controversial. In the coming years, promising potential methods to elucidate the predictors of BL allergy in children will require multidimensional approaches that may include predictive analytics, artificial intelligence techniques, and point-of-care clinical decision tools.

A combined risk modeling strategy for clinical prediction of beta-lactam allergies in children

Background: Drug provocation test (DPT) without skin tests is increasingly recommended in the evaluation of children with low-risk beta-lactam (BL) allergies. However, risk definitions are unclear. Objective: The aim of this study was to compose a clinical predictive model that could identify the children at low risk who could safely undergo direct DPT. Methods: The clinical data of 204 children who underwent a full diagnostic algorithm for suspected BL allergy were analyzed. Clinical data were used to construct mathematical predictive model for confirmed BL allergies. A prospective new sample was used for external validation of the final model. Results: The presentations during the index reaction were anaphylaxis in 5.9% and cutaneous reactions in the majority. BL allergy was confirmed in 15.7% of suspected cases. A backward multiple logistic regression model showed that a family history of drug allergy (adjusted odds ratio [aOR], 5.52), anaphylaxis (aOR, 5.14), any atopic disease other than asthma (aOR, 4.38), and a reaction interval of 0-6 hours during the index reaction (aOR, 5.32) were significantly associated with a confirmed BL allergy. A mathematical combined model based on these factors showed a sensitivity of 77.8% and a negative predictive value (NPV) of 94.3%. The validation study replicated sensitivity and NPV values of the main cohort. Conclusion: The risk definition in BL allergies should depend on population-specific predictive models, including a combination of significant risk factors rather than empiric risk approaches. This may help to accurately determinate children at low risk who may safely proceed to direct DPT.

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.

Towards a more precise diagnosis of hypersensitivity to beta-lactams - an EAACI position paper

A recent survey of the European Academy of Allergy and Clinical Immunology (EAACI) Drug Allergy Interest Group (DAIG) on how European allergy specialists deal with beta-lactam (BL) hypersensitivity demonstrated a significant heterogeneity in current practice, suggesting the need to review and update existing EAACI guidelines in order to make the diagnostic procedures as safe and accurate, but also as cost-effective, as possible. For this purpose, a bibliographic search on large studies regarding BL hypersensitivity diagnosis was performed by an EAACI task force, which reviewed and evaluated the literature data using the GRADE system for quality of evidence and strength of recommendation. The updated guidelines provide a risk stratification in BL hypersensitivity according to index reaction(s), as well as an algorithmic approach, based on cross-reactivity studies, in patients with a suspicion of BL hypersensitivity and an immediate need for antibiotic therapy, when referral to an allergist is not feasible. Furthermore, the update addresses availability and concentrations of skin test (ST) reagents, ST and drug provocation test (DPT) protocols, and diagnostic algorithms and administration of alternative BL in allergic subjects. Specifically, distinct diagnostic algorithms are suggested depending on risk stratification of the patient into high and low risk based on the morphology and chronology of the reaction, immediate (ie, occurring within 1-6 hours after the last administered dose) or nonimmediate (ie, occurring more than 1 hour after the initial drug administration), and the reaction severity. Regarding the allergy workup, the main novelty of this document is the fact that in some low-risk nonimmediate reactions ST are not mandatory, especially in children. For DPT, further studies are necessary to provide data supporting the standardization of protocols, especially of those regarding nonimmediate reactions, for which there is currently no consensus.

Accuracy of penicillin allergy diagnostic tests: A systematic review and meta-analysis

BACKGROUND

Having a penicillin allergy label associates with a higher risk for antibiotic resistance and increased health care use.

OBJECTIVE

We sought to assess the accuracy of skin tests and specific IgE quantification in the diagnostic evaluation of patients reporting a penicillin/β-lactam allergy.

METHODS

We performed a systematic review and diagnostic accuracy meta-analysis, searching on MEDLINE, Scopus, and Web of Science. We included studies conducted in patients reporting a penicillin allergy and in whom skin tests and/or specific IgE quantification were performed and compared with drug challenge results. We quantitatively assessed the accuracy of diagnostic tests with bivariate random-effects meta-analyses. Meta-regression and subgroup analyses were performed to explore causes of heterogeneity. Studies' quality was evaluated using QUADAS-2 criteria.

RESULTS

We included 105 primary studies, assessing 31,761 participants. Twenty-seven studies were assessed by bivariate meta-analysis. Skin tests had a summary sensitivity of 30.7% (95% CI, 18.9%-45.9%) and a specificity of 96.8% (95% CI, 94.2%-98.3%), with a partial area under the summary receiver-operating characteristic curve of 0.686 (I² = 38.2%). Similar results were observed for subanalyses restricted to patients reporting nonimmediate maculopapular exanthema or urticaria/angioedema. Specific IgE had a summary sensitivity of 19.3% (95% CI, 12.0%-29.4%) and a specificity of 97.4% (95% CI, 95.2%-98.6%), with a partial area under the summary receiver-operating characteristic curve of 0.420 (I² = 8.5%). Projected predictive values mainly reflect the low frequency of true penicillin allergy.

CONCLUSIONS

Skin tests and specific IgE quantification appear to have low sensitivity and high specificity. Because current evidence is insufficient for assessing the role of these tests in stratifying patients for delabeling, we identified key requirements needed for future studies.

Children with reported penicillin allergy: Public health impact and safety of delabeling

OBJECTIVE

To review the relevant literature related to children with reported penicillin allergy and highlight the different ways in which children could be delabeled and to evaluate the public health impact that a penicillin allergy has for children.

DATA SOURCES

Data for this review were obtained via PubMed searches and then retrieval of articles from their respective journals for further review.

STUDY SELECTIONS

Studies regarding the safety of different ways to evaluate penicillin allergy in children were identified via PubMed searches. Any study that reported different ways of testing (3-tier, direct oral challenge, 5-day oral challenges) were included. This same format was used when selecting relevant articg:les related to the costs, prescription patterns, and stewardship trends associated with a penicillin allergy label.

RESULTS

This review found that penicillin allergy testing is a safe and effective way to delabel those with reported allergy. In children with low-risk allergy symptoms, a direct oral challenge approach may be optimal. In those children with a history of high-risk allergy symptoms, a 3-tiered approach is ideal. The review also found that there is a significant cost associated with reported penicillin allergy and that there are increased negative health benefits to those children with reported allergy.

CONCLUSION

Penicillin allergy is overdiagnosed, often incorrectly, and the label is frequently first applied during childhood. Targeting children for the removal of the incorrect penicillin allergy label provides a mechanism to reduce the use of broader-spectrum and less effective antibiotics.

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.

Antibiotic Allergy in Pediatrics

The overlabeling of pediatric antibiotic allergy represents a huge burden in society. Given that up to 10% of the US population is labeled as penicillin allergic, it can be estimated that at least 5 million children in this country are labeled with penicillin allergy. We now understand that most of the cutaneous symptoms that are interpreted as drug allergy are likely viral induced or due to a drug-virus interaction, and they usually do not represent a long-lasting, drug-specific, adaptive immune response to the antibiotic that a child received. Because most antibiotic allergy labels acquired in childhood are carried into adulthood, the overlabeling of antibiotic allergy is a liability that leads to unnecessary long-term health care risks, costs, and antibiotic resistance. Fortunately, awareness of this growing burden is increasing and leading to more emphasis on antibiotic allergy delabeling strategies in the adult population. There is growing literature that is used to support the safe and efficacious use of tools such as skin testing and drug challenge to evaluate and manage children with antibiotic allergy labels. In addition, there is an increasing understanding of antibiotic reactivity within classes and side-chain reactions. In summary, a better overall understanding of the current tools available for the diagnosis and management of adverse drug reactions is likely to change how pediatric primary care providers evaluate and treat patients with such diagnoses and prevent the unnecessary avoidance of antibiotics, particularly penicillins.

Oral challenge without skin tests in children with non-severe beta-lactam hypersensitivity: Time to change the paradigm?

Suspected allergy to penicillins and cephalosporins is very common in childhood. After a proper evaluation, allergy will be confirmed only in a small portion of them. Intradermal tests are usually part of the allergy workup, but they are painful for children and time-consuming, and their role has been debated. A systematic review found only two studies reporting a positive predictive value of skin tests in children of 36% and 33%, respectively, leading to a high rate of inaccurate diagnosis. Moreover, considering that skin tests are negative in more than 90%-95% of cases, an oral provocation test (OPT) is finally needed to confirm tolerance in most of these children. Positive OPT are rare, and even where children demonstrate reproducible signs on challenge, they rarely constitute immediate or serious symptoms. Therefore, OPT to the index antibiotic without skin tests are increasingly being considered an accepted procedure for children with a suspected mild non-immediate reaction related to a beta-lactam antibiotic. Furthermore, a recent research has taken the same approach including children with suspected mild immediate reactions, with similar safety and positive results. In light of recent evidence highlighted, it is now the time for large and multicentric studies to confirm that OPT with the index antibiotic, without skin tests, are safe and convenient for children with a history of a mild reaction with a beta-lactam antibiotic before it can be recommended in pediatric allergy guidelines.

[Hypersensitivity reactions to beta-lactam antibiotics]

Allergy to beta-lactam antibiotics is a common condition and about 10% of patients report being allergic to penicillin. However, this diagnosis is largely overestimated. Two types of allergy should be distinguished and include immediate hypersensitivity that can lead to anaphylactic shock and delayed hypersensitivity, ranging from the most common maculopapular exanthema to severe bullous toxidermia or life-threatening DRESS. Allergy challenge with oriented skin tests according to the clinical features, supplemented with oral challenge in the absence of contraindication, will confirm or invalidate the diagnosis of beta-lactam allergy and will help to identify if necessary safe alternatives to beta-lactams.

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.

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.

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.

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.

Drug provocation tests in hypersensitivity drug reactions

PURPOSE OF REVIEW

Drug provocation test (DPT) is necessary to diagnose most drug hypersensitivity reactions (HSRs) due to decreased sensitivity of skin testing even when combined with in-vitro tests in immunonologic drug HSR and limited availability of these tests in nonimmunologic reaction. We review the principles and controversial issues of DPT, and recent studies using DPT as a diagnostic tool.

RECENT FINDINGS

DPT is recommended in the diagnosis of HSR to β-lactams, as well as other drug classes [such as acetylsalicylic acid-NSAIDs (ASA-NSAIDs), non-β-lactams antibiotics, heparin, glucocorticoids, and local anesthetic agents]. In view of the decreased sensitivity of skin testing, limited accessibility to new benzylpenicillin polylysine (PPL)/mixture of minor determinant (MDM) test reagents and limited availability of validated sensitive in-vitro tests, individuals who require DPT to β-lactams are increasing. The negative predictive value of allergologic work-up is very high, ranging from 94 to 98% for β-lactams and those reactions after negative tests are mostly nonimmediate and mild. Finally, DPT is recommended to ascertain tolerability of alternative compound when evaluating cross-reactivity among different classes of β-lactams, NSAIDs and glucocorticoids, and possibly iodinated contrast media.

SUMMARY

DPT is often needed when evaluating patients with suspected drug HSR. More studies regarding standardization of the various protocols are needed in order to increase its acceptance and adoption as a standard practice in the diagnostic algorithm for drug HSR.

Usefulness of drug provocation tests in children with a history of adverse drug reaction

Purpose

There are very few reports of adverse drug reactions (ADR) and almost no study of drug provocation test (DPT) in Korean children. We aimed to assess the role of DPT in children with unpredictable ADRs, and compare the causative drugs and clinical characteristics between detailed history of ADRs and result of DPTs.

Methods

We included 16 children who were experienced ADRs referred to pediatric allergy clinic at Ajou University Hospital (January 2006 to December 2009). With various suspected drugs, 71 DPTs were done in 16 patients using our own protocol, and skin tests to antibiotics were combined in ADRs to antibiotics in medical history.

Results

There were 17 (23.9%) positive DPTs results out of 71 individual DPTs, and 11 patients (68.8%) from 16 patients were positive to at least one drug. Drugs causing positive reactions were acetaminophen in 5 (31%), Non-steroidal anti-inflammatory drugs in 4 (25%), penicillin in 3 (19%), cephalosporin in 2 (13%), and cotrimoxazole, macrolide and lactose in 1 each.

Conclusion

DPT seems a safe and useful procedure to confirm causative drug and identify safely administering alternative drugs in children with ADR.