β-Lactam allergy delabeling is safe and saves costs in Primary Care

Abstract

Objective: To determine whether the -lactam allergy delabeling was safe and cost-saving in Primary Care (PC) patients. Design: We have conducted a retrospective chart review of PC patients with -lactam allergy label evaluated in our Allergy Unit between 2017 and 2022. Site: Allergy Department. Hospital Virgen del Rocio (Sevilla). Participants: A total of 391 patients labeled for -lactam allergy in PC were studied. Main measurements: (a) Outcome evaluation of a -lactam allergy delabeling procedure. (b) A ratio between the total e-prescribed antibiotic cost and the number of treatment days (the experimental daily antibiotic cost or EDAC) before and after delabeling was analyzed in delabeled and truly allergic patients. Results: The results of skin testing were positive in 9.2% of the reported cases (36 of 391 patients). The reactions to oral provocation challenge (OPC) occurred in 2.14% of the patients who underwent negative skin testing to offending -lactam (in 15 of 699 OPC). A total of 307 patients (78.5%) were delabeled; 70 (17.9%) had a -lactam selective response and 14 (3.59%) reacted to both penicillin and cephalosporin. The EDAC before and after the procedure in delabeled patients was significantly lower (0.88 D vs 0.62 D , p < 10−3), than that observed in truly allergic group (0.87 D vs. 0.76 D , p = not significant). Conclusion: To delabel -lactam allergy in Primary Care patients is safe in most patients, costsaving in antibioticotherapy, and allows identify the main clinical -lactam allergy phenotypes that benefit from this procedure.