[Glycopeptide-induced cutaneous adverse reaction: results of an immunoallergic investigation in eight patients]

EAACI/ENDA position paper on drug provocation testing

In drug hypersensitivity, drug provocation testing (DPT), also called drug challenge, is the gold standard for investigation. In recent years, risk stratification has become an important tool for adjusting the diagnostic strategy to the perceived risk, whilst still maintaining a high level of safety for the patient. Skin tests are recommended before DPT but may be omitted in low-risk patients. The task force suggests a strict definition of such low-risk patients in children and adults. Based on experience and evidence from studies of allergy to beta-lactam antibiotics, an algorithm on how to adjust DPT to the risk, and when to omit skin tests before DPT, is presented. For other antibiotics, non-steroidal anti-inflammatory drugs and other drugs, skin tests are poorly validated and DPT is frequently necessary. We recommend performing DPT with chemotherapeutics and biologicals to avoid unnecessary desensitization procedures and DPT with skin tests negative contrast media. We suggest DPT with anesthetics only in highly specialized centers. Specifics of DPT to proton pump inhibitors, anticonvulsants and corticosteroids are discussed. This position paper provides general recommendations and guidance on optimizing use of DPT, whilst balancing benefits with patient safety and optimizing the use of the limited available resources.

Recent advances in the understanding of severe cutaneous adverse reactions

Severe cutaneous adverse reactions (SCARs) encompass a heterogeneous group of delayed hypersensitivity reactions, which are most frequently caused by drugs. Our understanding of several aspects of SCAR syndromes has evolved considerably over the last decade. This review explores evolving knowledge of the immunopathogenic mechanisms, pharmacogenomic associations, in vivo and ex vivo diagnostics for causality assessment, and medication cross-reactivity data related to SCAR syndromes. Given the rarity and severity of these diseases, multidisciplinary collaboration through large international, national and/or multicentre networks to collect prospective data on patients with SCAR syndromes should be prioritized. This will further enhance a systematized framework for translating epidemiological, clinical and immunopathogenetic advances into preventive efforts and improved outcomes for patients.

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.

Antimicrobial stewardship's new weapon? A review of antibiotic allergy and pathways to 'de-labeling'

PURPOSE OF REVIEW

The continued emergence of multiresistant pathogens and widespread antimicrobial use has led to a greater emphasis on antimicrobial stewardship programs. Concurrently, an increased awareness of the rising number of antibiotic allergy labels and impact on antimicrobial use has surfaced. The integration of antibiotic allergy de-labeling and antimicrobial stewardship programs may be a pathway worthy of further focus and investigation.

RECENT FINDINGS

Recent literature has evaluated the efficacy of antibiotic allergy management (historical de-labeling, in-vitro testing, skin prick testing, intradermal testing, and oral challenges) and impact of antibiotic allergy labels on patient outcome. The importance of true and perceived antibiotic allergy cross-reactivity in the setting of β-lactam allergies has been highlighted. The impact of dedicated antibiotic allergy de-labeling clinics, inpatient antibiotic allergy testing, and integrated antimicrobial stewardship programs has been recently appraised.

SUMMARY

More recent literature supports that appropriate antibiotic allergy in-vitro and in-vivo testing and subsequent antibiotic allergy de-labeling, particularly in regard to β-lactams, can decrease broad-spectrum antibiotic use, costs, patient length of stay, and mortality. Integration of antibiotic allergy management into the decision support systems of inpatient and outpatient antimicrobial stewardship programs represents an important opportunity to further improve measured outcomes from antibiotic utilization.

Fluindione and drug reaction with eosinophilia and systemic symptoms: an unrecognised adverse effect?

PURPOSE

Fluindione is an oral vitamin K antagonist (indanedione derivative) exclusively marketed in France and Luxembourg, known to have immuno-allergic adverse effects such as hepatitis, fever or interstitial nephritis. A few cases of drug reaction with eosinophilia and systemic symptoms (DRESS) have been reported with fluindione. The aim of the present study was to investigate fluindione-induced DRESS cases reported in France and to describe their characteristics.

METHODS

We searched for potential cases of DRESS with fluindione reported in the French pharmacovigilance database since 2000.

RESULTS

Thirty-six cases of DRESS were included and concerned 17 women and 19 men. The mean age was 65 years (median: 68 years, range: 28-95 years). Kidneys and liver were the most frequent organs involved. Thirty-five cases were serious. In 5 cases, the effect was life-threatening. Most of the patients recovered. Fluindione was the only medicine suspected in 26 cases. Skin patch tests, performed in 10 cases, were positive with fluindione in 9 cases.

CONCLUSIONS

Fluindione is not known to be a frequent cause of DRESS. However, the number of reports found is probably underestimated. The seriousness of DRESS, as all immuno-allergic adverse effects, contraindicates fluindione reintroduction. Coumarinic derivatives are the alternatives in patients who need oral anticoagulant treatment.

Vancomycin-associated spontaneous cutaneous adverse drug reactions

Purpose

With the increase in vancomycin use, adverse drug reactions (ADRs) associated with vancomycin have been reported increasingly more often. However, the characteristics of cutaneous ADRs with and without systemic reactions (SRs) have not been described. This study investigated the characteristics of spontaneously reported and assessed ADRs associated with vancomycin by a pharmacovigilance center.

Methods

ADRs (n=121) associated with vancomycin in 96 patients were collected from 2008 to 2009. Records from physician- and nurse-reported suspected cases of vancomycin ADRs, ADR type, latent period, and laboratory results were compared between cutaneous ADRs with and without SRs.

Results

The main vancomycin-related ADRs were skin rashes (47.9%), hematologic abnormalities (17.36%), fever (12.4%), and elevated serum creatinine (12.4%). Significant differences were observed in latent period (days) and the mean change in eosinophils (%) between cutaneous (9.21±9.71 and 1.4±3.4, respectively) and other ADRs (14.03±11.71 and -0.5±3.5, respectively). Twelve cases of cutaneous ADRs with SRs had been initially reported as cutaneous ADRs only. Mean changes in the eosinophil count were significantly higher for cutaneous ADRs with SRs compared to those without SRs.

Conclusions

Skin rashes accompanied by peripheral eosinophilia, representing suspected immune-mediated delayed hypersensitivity reactions, are a common vancomycin ADR. For the early and exact detection of ADRs associated with vancomycin administration, close monitoring of laboratory tests, including complete blood counts with differential analysis, is recommended.