A systematic review and meta-analysis of interventions to delabel low-risk penicillin allergies with consideration for sex and gender.

Aims: Sex and gender may influence penicillin allergy label (PAL) prevalence and outcomes. This review evaluates the effectiveness and safety of direct delabelling (DD) and oral challenge (OC) for low-risk patients and examines sex and gender differences in reporting and outcomes.

Methods: We searched PubMed, Database of Abstracts of Reviews and Effects, ClinicalTrials.gov, Cochrane Database of Systematic Reviews, International Pharmaceutical Abstracts, medRxiv, Ovid MEDLINE, and Ovid EMBASE until February 2024 for studies including DD or OC compared to no intervention, skin testing or other methods. Two reviewers assessed quality. Meta-analyses were conducted, and subgroup analyses were carried out if I² >   75%. Descriptive data was analysed using NVivo 14 and reported narratively.

Results: From 1046 screened studies, 28 met inclusion criteria (two RCTs, 26 quasi-experimental studies). Sex at baseline was reported in 86% of studies, with 61% females: 18% disaggregated outcomes by sex with a female mean delabelling rate of 66%. Gender variables were not reported. OC was not found to be more or less as effective comparaed to skin testing in RCTs (risk ratio [RR] 1.04; 95% confidence interval [CI] 0.95, 1.13, I² = 74%). DD interventions had a 27% delabelling rate (95% CI 10%, 50%, I² = 96%), with nursing staff achieving 29% (95% CI 15%, 47%, I² = 63%) and allergists/immunologists 6% (95% CI 0.00, 0.00, I² = 20%). Quasi-experimental studies reported 90% delabelling for OC, with 59% by allergists/immunologists and 90% by pharmacists. Adverse events averaged 4% and were non-severe.

Conclusions: DD and OC are effective for delabelling low-risk penicillin allergies. Comprehensive data is lacking on sex and gender differences, indicating a need for further research.