Work up of patients with history of beta-lactam hypersensitivity

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.

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.

The 3 Cs of Antibiotic Allergy-Classification, Cross-Reactivity, and Collaboration

Antibiotic allergy labeling is highly prevalent and negatively impacts patient outcomes and antibiotic appropriateness. Reducing the prevalence and burden of antibiotic allergies requires the engagement of key stakeholders such as allergists, immunologists, pharmacists, and infectious diseases physicians. To help address this burden of antibiotic allergy overlabeling, we review 3 key antibiotic allergy domains: (1) antibiotic allergy classification, (2) antibiotic cross-reactivity, and (3) multidisciplinary collaboration. We review the available evidence and research gaps of currently used adverse drug reaction classification systems, antibiotic allergy cross-reactivity, and current and future models of antibiotic allergy care.

Allergy test outcomes in patients self-reported as having penicillin allergy: Two-year experience

BACKGROUND

Penicillin allergy is associated with increased antibiotic resistance and health care costs. However, most patients with self-reported penicillin allergy are not truly allergic.

OBJECTIVE

To summarize our experience with allergy tests in patients with a history of penicillin allergy and to compare them with the results of other groups.

METHODS

We retrospectively reviewed all patients with a suspected clinical history of penicillin allergy referred to the Drug Allergy Unit at University College London Hospital between March 2013 and June 2015.

RESULTS

In total, 84 patients were reviewed. The index drugs included: unidentified penicillin (n = 44), amoxicillin (n = 17), amoxicillin-clavulanic acid (n = 13), flucloxacillin (n = 4), and other penicillins (ampicillin, benzylpenicillin, piperacillin-tazobactam; n = 7). Allergy diagnoses were confirmed in 24 patients (28.6%) (16 to penicillin, 3 to flucloxacillin, 5 to clavulanic acid). Twenty-two patients (91.7%) had allergy diagnosed by positive skin test results. Two patients (8.3%) developed IgE-mediated allergic symptoms during oral challenge (although the skin test results were negative). In vitro specific IgE test results for penicilloyl V, penicilloyl G, and amoxicilloyl were positive in 3 of 16 patients (18.8%). Moreover, reactions to cefuroxime were observed in 3 of 15 patients with penicillin allergy (20%). Selective clavulanic acid and flucloxacillin responders tolerated amoxicillin challenge. The interval between the index reaction and evaluation was shorter (P < .001), and the proportion of patients who could recall the name of the culprit drug was higher (P = .009) in the allergic group. Furthermore, histories of anaphylaxis (33.3%), urticaria, and/or angioedema (58.3%) were more common in the allergic group. Unspecified rashes (35.0%) and nonspecific symptoms (28.3%) predominated in the nonallergic group.

CONCLUSION

Only 28.6% of patients with self-reported penicillin allergy were confirmed to be allergic. Importantly, when the index drug is amoxicillin-clavulanic acid or flucloxacillin, the patients may tolerate amoxicillin.

A retrospective comparison of false negative skin test rates in penicillin allergy, using pencilloyl-poly-lysine and minor determinants or Penicillin G, followed by open challenge

Background

A history of penicillin allergy in patients is common, but only 10–15 % are truly allergic. While the gold standard for diagnosing penicillin allergy is challenge, it is not recommended that this be done without first carrying out diagnostic skin testing. This is carried out with the major determinant benzylpenicilloyl (PPL) and the minor determinant mixture (MDM), consisting of penilloate, penicilloate and Penicillin G. However, since availability of the MDM is limited, Penicillin G alone has been used.

Methods

A retrospective chart review was carried out on patients tested for penicillin allergy in the Clinical Immunology and Allergy Clinic at the Health Sciences Centre, Winnipeg, Canada between 2005 and 2013. A total of 521 patients charts were reviewed, of whom 240 had skin testing, ImmunoCap^® for IgE to Penicillin G and V and had oral challenges with penicillin, amoxicillin or cloxacillin.

Results

17/240 (7.5 %) were skin test positive, 8 to PPL, 4 to MDM and 5 to Penicillin G. One was also positive on ImmunoCap^® testing. Three patients had negative skin tests but weakly positive ImmunoCap^®. 222 patients with negative skin tests and serological tests were challenged. Of these, 12 patients reacted to challenge. Three of the challenges were equivocal. Of the nine patients with definite positive challenges, three were tested with Penicillin G and six with MDM. Therefore the false negative rates for testing were 2.3 % with PPL and Penicillin G and 6.97 % for PPL and MDM. The difference was not significant (p = 0.0856).

Conclusions

In this group of patients with a history of penicillin allergy tested with the major determinant of benzyl penicillin and either MDM or Penicillin G, there was no difference in the rate of false negative testing, based on oral penicillin challenges. Therefore, Penicillin G can be safely used as an alternative to MDM in diagnosing penicillin allergy.

Penicillin allergy evaluation: experience from a drug allergy clinic in an Arabian Gulf Country, Kuwait

BACKGROUND

Hypersensitivity to penicillin has been studied worldwide, but data regarding patterns of sensitization in Arabian Gulf countries are scarce.

OBJECTIVE

To describe the patterns of penicillin hypersensitivity during a 6-year study in Kuwait in terms of demographics, type of the culprit drug, in vivo and in vitro allergy testing.

METHODS

One hundred and twenty-four patients referred to the drug allergy clinic for penicillin allergy were fully evaluated by skin prick and intradermal testing. Drug provocation test was done on patients with negative results.

RESULTS

A total of 124 patients were evaluated for penicillin allergy. Mean age was 37.8 (standard deviation, 12.7) years, range from 8 to 74 years. Thirty-nine male (31.5%) and 85 female patients (68.5%) were included. Diagnosis of penicillin allergy was confirmed in 46 patients (37.1%). Among the 44 confirmed allergic patients by skin evaluation we had 15 (34.1%) positive skin prick test, and 29 (65.9%) positive intradermal testing. Among patients with positive skin testing, 47.7% were positive to major determinant benzylpenicilloyl poly-L-lysine, 20.4% to minor determinant mixture, 50.0% to penicillin G and 40.9% to ampicillin; 13.6% of patients were positive to amoxicillin by skin prick test. One patient had a positive radioallergosorbent test and one had a positive challenge test.

CONCLUSION

Penicillin allergy is a common problem with an incidence of about one third in our study subjects.

Peri-operative anaphylaxis

Peri-operative anaphylaxis is an important cause for mortality and morbidity associated with anaesthesia. The true incidence is unknown and is most likely under reported. Diagnosis can be difficult, particularly as a number of drugs are given simultaneously and any of these agents can potentially cause anaphylaxis. This review covers the clinical features, differential diagnosis and management of anaphylaxis associated with anaesthesia. The investigations to confirm the clinical suspicion of anaphylaxis and further tests to identify the likely drug(s) are examined. Finally the salient features of common and rare causes including non-drug substances are described.

Use of commercial anti-penicillin IgE fluorometric enzyme immunoassays to diagnose penicillin allergy

BACKGROUND

The intermittent unavailability of penicilloyl-polylysine since September 2000 has focused interest on commercial anti-penicillin IgE fluorometric enzyme immunoassay (FEIA) tests to evaluate penicillin allergy. There has been no published comparison of commercial anti-penicillin IgE FEIAs and penicillin skin testing performed in the United States.

OBJECTIVE

To determine whether the current commercial anti-penicillin IgE FEIAs can replace or augment penicillin skin testing and oral challenges when evaluating individuals with a history of penicillin allergy for future therapeutic penicillin tolerance.

METHODS

A prospective convenience sample of 150 individuals with a history of penicillin allergy were evaluated between January 23, 2007, and August 4, 2009, with both penicillin skin tests and commercial anti-penicillin IgE FEIAs to penicillin G, penicillin V, and amoxicillin. All individuals with a negative penicillin skin test result underwent oral penicillin class antibiotic challenges. All individuals with a positive anti-penicillin IgE FEIA result also underwent oral penicillin class antibiotic challenges.

RESULTS

Six individuals (4.0%; 95% confidence interval [CI], 0.9% to 7.1%) had positive penicillin skin test results, and none had positive FEIA results. Four individuals (2.7%; 95% CI, 0.1% to 5.3%) had positive FEIA results, and none had positive penicillin skin test results. Three individuals (2.0%; 95% CI, -0.2% to 4.2%) had positive oral challenge results, 1 with hives at 6 hours after challenge and 2 with delayed-onset (at >24 hours) nonurticarial rashes, and none had positive FEIA results.

CONCLUSIONS

The current commercial anti-penicillin IgE FEIAs are not useful in diagnosing penicillin allergy in patients with remote histories of penicillin allergy. Penicillin skin testing and, if the results are negative, an oral challenge remain the criterion standard tests to determine therapeutic penicillin tolerance.