Evaluation of desensitization protocols to betalactam antibiotics

Cephalosporin Allergy: Updates on Diagnostic Testing

PURPOSE OF REVIEW

Cephalosporins are one of the most prescribed antibiotics worldwide and are implicated in a wide range of hypersensitivity reactions (HSR). This review summarizes recent updates in cephalosporin hypersensitivity with a focus on diagnostic testing.

RECENT FINDINGS

Reported testing strategies to evaluate different immediate and delayed cephalosporin HSR have included skin testing, in vitro testing, and diagnostic drug challenges. However, the diagnostic performance of in vivo and in vitro tests remains unclear across different hypersensitivity endotypes; adequately powered studies investigating the true positive and negative predictive value of these diagnostic modalities are needed using the reference standard of drug challenges to define cephalosporin hypersensitivity. Refinement of diagnostic testing should be guided by growth in our understanding of cephalosporin antigenic determinants. This growth will be crucial in driving further clarification of cross-reactivity between cephalosporins, and potentially delineating streamlined evaluation processes resulting in reduced unnecessary antibiotic avoidance.

A retrospective case-control study to evaluate the use of beta-lactam desensitization in the management of penicillin-allergic patients: a potential strategy for Antimicrobial Stewardship Programs

Introduction: Penicillin allergy labels (PAL) are common in the hospital setting and are associated with worse clinical outcomes. Desensitization can be a useful strategy for allergic patients when alternative options are suboptimal or not available. The aim was to compare clinical outcomes of patients with PAL managed with antibiotic desensitization vs. those who received alternative non-beta-lactam antibiotic treatments. Methods: A retrospective 3:1 case-control study was performed between 2015-2022. Cases were adult PAL patients with infection who required antibiotic desensitization; controls were PAL patients with infection managed with an alternative antibiotic treatment. Cases and controls were adjusted for age, sex, infection source, and critical or non-critical medical services. Results: Fifty-six patients were included: 14 in the desensitization group, 42 in the control group. Compared to the control group, desensitized PAL patients had more comorbidities, with a higher Charlson index (7.4 vs. 5; p = 0.00) and more infections caused by multidrug-resistant (MDR) pathogens (57.1% vs. 28.6%; p = 0.05). Thirty-day mortality was 14.3% in the desensitized group, 28.6% in the control group (p = 0.24). Clinical cure occurred in 71.4% cases and 54.8% controls (p = 0.22). Four control patients selected for MDR strains after alternative treatment; selection of MDR strains did not occur in desensitized patients. Five controls had antibiotic-related adverse events, including Clostridioides difficile or nephrotoxicity. No antibiotic-related adverse events were found in the study group. In multivariate analysis, no differences between groups were observed for main variables. Conclusion: Desensitization was not associated with worse clinical outcomes, despite more severe patients in this group. Our study suggests that antibiotic desensitization may be a useful Antimicrobial Stewardship tool for the management of selected PAL patients.