Can fluoroquinolones be safely used in patients with immediate hypersensitivity reaction to penicillin?

Objective: The aim of this study was to evaluate whether fluoroquinolone antibiotics, which are structurally distinct from penicillins, can be safely prescribed as alternatives for patients with a history of immediate-type hypersensitivity reactions (HSRs) to penicillin in the absence of multidrug allergy and without the need for provocation testing.

Methods: We conducted a retrospective analysis of the medical records of patients who presented to the Erciyes University Adult Immunology and Allergy Outpatient Clinic with a documented history of penicillin allergy between 2015 and 2024. Inclusion criteria for immediate hypersensitivity to penicillin included at least one of the following: (1) a history of at least two separate immediate HSRs to the same penicillin; or (2) positive results from penicillin G/V (Penicillin G and Penicillin V) serum-specific immunoglobulin E (SsIgE) and/or skin prick testing. Patients who met these criteria and subsequently underwent oral provocation testing with fluoroquinolone antibiotics were included in the study.

Results: This study included 76 patients (72% female, mean age: 45.63 ± 11.76 years), 47.4% of whom had comorbid allergic diseases. The diagnosis was primarily based on clinical history (80%), while the remainder were confirmed by SsIgE testing, skin tests, or drug provocation. A history of urticaria-angioedema was reported in 59.2% of the patients, while 40.8% had a history of anaphylaxis. Following oral provocation testing with fluoroquinolones, only two patients (2.6%) developed mild, self-limited urticaria or angioedema, without systemic involvement.

Conclusions: Our study demonstrates a low positive rate (2.6%) for fluoroquinolone oral provocation testing among patients with penicillin allergy. These findings suggest that fluoroquinolones may be a viable and safe alternative in patients with a confirmed penicillin hypersensitivity and no history of multidrug allergy, and may be considered without prior provocation testing in selected cases.