Related Experiment Video
Updated: Jun 13, 2026
07:13
Quantification of Violacein in Chromobacterium violaceum and Its Inhibition by Bioactive Compounds
Published on: August 8, 2025
Negative Test, Persistent Avoidance: Real-World Outcomes of Quinolone De-Labeling
Kutay Kırdök1, Ceyda Tunakan Dalgıç1, Ragıp Fatih Kural1
1Division of Immunology and Allergy, Department of Internal Medicine, Faculty of Medicine, Ege University, 35100 İzmir, Türkiye.
Journal of Clinical Medicine
|June 12, 2026
Summary
Diagnosing quinolone hypersensitivity is challenging. While skin tests have low specificity, successful allergy de-labeling doesn't ensure patients will reuse the antibiotic due to anxiety.
Area of Science:
- Allergy and Immunology
- Pharmacology
Background:
- Quinolones are frequently implicated in immediate hypersensitivity reactions.
- Diagnostic evaluation and real-world patient behavior post-de-labeling are understudied.
Purpose of the Study:
- To examine the diagnostic work-up for suspected quinolone hypersensitivity.
- To assess patient outcomes and drug-use behavior after allergy de-labeling.
Main Methods:
- Single-center ambispective study of 29 patients evaluated for quinolone hypersensitivity.
- Retrospective data extraction of clinical, demographic, skin tests, and drug provocation tests (DPT).
- Structured telephone interviews with patients post-de-labeling.
Main Results:
- Anaphylaxis was the most common reaction; ciprofloxacin was the most frequent agent.
- Skin tests showed high positivity (84.2%) but low positive predictive value (20.0% in DPT-tested subset).
- Of 12 interviewed, 11 had allergy excluded; only 36.4% reused the de-labeled quinolone.
Conclusions:
- Quinolone skin tests have limited specificity.
- Successful de-labeling does not guarantee real-world quinolone reuse.
- Patient anxiety and counseling are critical for managing quinolone hypersensitivity.
Related Concept Videos
01:28Inhibitors of Bacterial DNA Synthesis
Bacterial pathogens depend on precise and efficient DNA replication to sustain infection. Two type II topoisomerases—DNA gyrase and topoisomerase IV—are critical to this process, as they resolve DNA supercoiling and unlink chromosomes during replication. Fluoroquinolones, synthetic derivatives of quinolones, exploit this mechanism by stabilizing the transient DNA–enzyme cleavage complex, preventing strand religation, and causing lethal double-strand breaks. These antibiotics are selectively...
01:28Gene Regulation in Microbial Communities: Quorum Sensing
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
01:25Clinical Significance of Antibiotic Resistance
Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...
01:19Pharmacovigilance
Post-marketing surveillance is a critical component of pharmaceutical regulation, often uncovering unanticipated adverse drug reactions (ADRs) once a drug is widely used over an extended period.
This process, termed pharmacovigilance, aims to detect, evaluate, and minimize harmful effects related to medication use. The data collection for pharmacovigilance depends on spontaneous reporting systems, where healthcare professionals or patients voluntarily report suspected ADRs.
In some cases, there...
This process, termed pharmacovigilance, aims to detect, evaluate, and minimize harmful effects related to medication use. The data collection for pharmacovigilance depends on spontaneous reporting systems, where healthcare professionals or patients voluntarily report suspected ADRs.
In some cases, there...
01:26Urine Studies II: Urine Culture and Sensitivity Test
A urine culture and sensitivity test is a diagnostic procedure used to identify urinary tract bacterial infections and determine the most effective antibiotics for treatment. This test is generally preferred when a patient shows manifestations of a urinary tract infection, such as frequent or painful urination, cloudy or foul-smelling urine, or lower abdominal pain.Purpose of the TestThe primary goals of a urine culture and sensitivity test are to:Determine the specific bacteria causing the...
01:20Desensitization and Tachyphylaxis
Tachyphylaxis is described as a rapid decrease in response to a drug after repeated or continuous administration of the same drug dose. It is a phenomenon where the body becomes less responsive to a particular substance or intervention over time, requiring higher doses or stronger interventions to achieve the same effect. It results from adaptive changes in the body's receptors, signaling pathways, or physiological processes that occur in response to prolonged exposure to a stimulus.
Several...
Several...