Outcome of a de-labelling algorithm compared with results of penicillin (β-lactam) allergy testing

Delabeling of allergy to beta-lactam antibiotics in hospitalized patients: a prospective study evaluating cost savings

BACKGROUND

Patients with a penicillin allergy label are at risk of an associated increase in adverse antibiotic events and hospitalization costs.

AIM

We aimed to study the economic savings derived from the correct diagnosis and delabeling inpatients with suspected beta-lactam allergy, considering the acquisition cost of antimicrobials prescribed during a patient's hospital stay.

METHOD

We prospectively evaluated patients admitted to the University Hospital of Salamanca who had been labeled as allergic to beta-lactams and performed a delabeling study. Subsequently, cost differences between antibiotics administered before and after the allergy study and those derived from those patients who received alternative antibiotics during admission and those who switched to beta-lactams after the allergy study were calculated.

RESULTS

One hundred seventy-seven inpatients labeled as allergic to beta-lactams underwent a delabeling study; 34 (19.2%) were confirmed to have allergy to beta-lactams. Of the total number of patients, 136 (76.8%) received antibiotics during their hospitalization, involving a mean (SD) cost of €203.07 (318.42) and a median (IQR) cost of €88.97 (48.86-233.56). After delabeling in 85 (62.5%) patients, the antibiotic treatment was changed to beta-lactams. In this group of patients, the mean cost (SD) decreased from €188.91 (351.09) before the change to 91.31 (136.07) afterward, and the median cost (IQR) decreased from €72.92 (45.82-211.99) to €19.24 (11.66-168). The reduction was significant compared to the median cost of patients whose treatment was not changed to beta-lactams (p<0.001).

CONCLUSION

Delabeling hospitalized patients represents a cost-saving measure for treating patients labeled as allergic to beta-lactams.

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.

Preparation of three-dimensional ordered macroporous Ag/LaFeO3 and heterogeneous photo-Fenton degradation of penicillin G potassium

3DOMLaFeO3 was prepared by template method combined with sol-gel method using monodisperse polystyrene (PS) microspheres as template, and Ag/3DOMLaFeO3 perovskite catalyst was prepared by impregnation method combined with sodium borohydride reduction method. The catalysts were characterised by means of TG, XRD, SEM, BET, XPS, UV-vis DRS, etc. The photo-Fenton catalytic performance, stability and catalytic reaction mechanism of Ag/3DOMLaFeO3 were studied with penicillin G potassium (PEN G) as the model pollutant. The results indicated that the as-prepared Ag/3DOMLaFeO3 exhibited a three-dimensional ordered macroporous (3DOM) structure, and the light capture and mass transfer were enhanced through abundant pores and large specific surface area. Based on the surface plasmon resonance effect (SPR), Ag loading enhanced the absorption of the material in the visible light region, and inhibited the recombination of photogenerated carriers, which improved the photocatalytic performance of 3DOMLaFeO3 under visible light. Under the conditions of hydrogen peroxide dosage of 1.5 mL·L-1, initial pH of 5, PEN G initial concentration of 100 mg·L-1, catalyst dosage of 300 mg·L-1, xenon lamp irradiation, the degration ratio of PEN G and the removal rate of TOC reached 99.99% and 85.45% within 120 min, respectively. In addition, it had a wide range of pH application, excellent stability and practical application value. The quenching experiment and ESR test showed that ·OH and ·O2- were the reasons for high catalytic degradation. The least square method was used to fit the experimental data, and the results displayed that the degradation of PEN G was approximately in line with the first-order kinetic reaction.

Barriers to penicillin allergy de-labeling in the inpatient and outpatient settings: a qualitative study

BACKGROUND

Penicillin allergy is the most commonly reported drug allergy in the US. Despite evidence demonstrating that up to 90% of labels are incorrect, scalable interventions are not well established. As part of a larger mixed methods investigation, we conducted a qualitative study to describe the barriers to implementing a risk-based penicillin de-labeling protocol within a single site Veteran's hospital.

METHODS

We conducted individual and group interviews with multidisciplinary inpatient and outpatient healthcare teams. The interview guides were developed using the Theoretical Domains Framework (TDF) to explore workflows and contextual factors influencing identification and evaluation of patients with penicillin allergy. Three researchers iteratively developed the codebook based on TDF domains and coded the data using thematic analysis.

RESULTS

We interviewed 20 clinicians. Participants included three hospitalists, five inpatient pharmacists, one infectious disease physician, two anti-microbial stewardship pharmacists, four primary care providers, two outpatient pharmacists, two resident physicians, and a nurse case manager for the allergy service. The factors that contributed to barriers to penicillin allergy evaluation and de-labeling were classified under six TDF domains; knowledge, skills, beliefs about capabilities, beliefs about consequences, professional role and identity, and environmental context and resources. Participants from all groups acknowledged the importance of penicillin de-labeling. However, they lacked confidence in their skills to perform the necessary evaluations, such as test dose challenges. The fear of inducing an allergic reaction and adding further complexity to patient care exacerbated their reluctance to de-label patients. The lack of ownership of de-labeling initiative was another significant obstacle in establishing consistent clinical workflows. Additionally, heavy workloads, competing priorities, and ease of access to alternative antibiotics prevented the prioritization of tasks related to de-labeling. Space limitations and nursing staff shortages added to challenges in outpatient settings.

CONCLUSION

Our findings demonstrated that barriers to penicillin allergy de-labeling fall under multiple behavioral domains. Better role clarification, opportunities to develop necessary skills, and dedicated resources are needed to overcome these barriers. Future interventions will need to employ a systemic approach that addresses each of the behavioral domains influencing penicillin allergy de-labeling with stakeholder engagement of the inpatient and outpatient health care teams.

Guideline for allergological diagnosis of drug hypersensitivity reactions: S2k Guideline of the German Society for Allergology and Clinical Immunology (DGAKI) in cooperation with the German Dermatological Society (DDG), the Association of German Allergologists (ÄDA), the German Society for Pediatric Allergology (GPA), the German Contact Dermatitis Research Group (DKG), the German Society for Pneumology (DGP), the German Society of Otorhinolaryngology, Head and Neck Surgery, the Austrian Society of Allergology and Immunology (ÖGAI), the Austrian Society of Dermatology and Venereology (ÖGDV), the German Academy of Allergology and Environmental Medicine (DAAU), and the German Documentation Center for Severe Skin Reactions (dZh)

Not available.

Advances in the Understanding of Drug Hypersensitivity: 2012 Through 2022

Over the last decade there have been key advances in understanding mechanisms, risk, and consequences of both true immunological drug hypersensitivity and unverified drug allergy labels that have changed clinical practice. This has been facilitated by the widespread adoption of electronic health records (EHRs). The vast majority of EHR drug allergy labels are unverified and cause significant morbidity from unnecessary avoidance of optimal drug therapy. There has also been significant movement in our understanding of mechanisms of drug hypersensitivity that, in addition to advancing our understanding of the pathogenesis of immediate and delayed reactions, have guided preventive efforts, diagnostic procedures, and clinical management. More widespread adoption, including scale-up of "allergy" delabeling and appropriate management, specifically for antibiotics, opiates, radiocontrast, chemotherapeutics, biologics, and nonsteroidal anti-inflammatory medications, will be necessary to improve patient outcomes over the next decade. This will require further engagement and collaboration between primary care health care providers, allergists, and other specialists.

Patients with questionable penicillin (beta-lactam) allergy: Causes and solutions

BACKGROUND

In Europe, North America, and Australia, 5% to 10% of the population are now classified as penicillin (β-lactam) allergic. Only ~ 10% of these questionable diagnoses, mostly made in childhood, can be confirmed by allergy diagnostics.

MATERIALS AND METHODS

The aim of this review is to show causes and consequences as well as recommendations for dealing with the often questionable diagnosis of penicillin (β-lactam) allergy (BLA).

RESULTS

An incorrect BLA diagnosis may negatively impact antibiotic treatment needed in the future, by using a less effective antibiotic or using a broad-spectrum antibiotic, for example, further exacerbating the problem of increasing antibiotic resistance. Accordingly, there is growing pressure from antibiotic stewardship programs to critically challenge the BLA diagnosis. Conservatively, a suspected BLA is reviewed by an allergist using medical history, skin testing, laboratory testing, and provocation. This clarification is costly and is not remunerated in the German health care system; that is the reason why this testing is only offered in a few specialized clinics and practically not at all in general practice. In view of thousands of affected patients, additional strategies are needed to treat patients with a low risk of hypersensitivity reaction despite suspected allergy with a β-lactam antibiotic. In recent years, various methods have been proposed to eliminate suspected allergy as promptly as possible and directly before necessary treatment with a β-lactam antibiotic, including standardized history (also in the form of an algorithm), skin test with immediate reading after 15 minutes, or administration of a small test dose. Investigations of small case series and also multi-center studies to date have yielded promising results in terms of feasibility and safety.

CONCLUSION

Of the large number of patients with (questionable) BLA, most have never been tested and - if antibiotic treatment becomes necessary - simply receive an alternative antibiotic. The diagnosis of BLA therefore requires new approaches besides classical allergy testing to critically question BLA.