title: Allergy to quinolones: low cross-reactivity to levofloxacin.
abstract: BACKGROUND
  Immediate-type hypersensitivity reactions to quinolones are rare. Some reports describe the presence of cross-reactivity among different members of the group, although no predictive pattern has been established. No previous studies confirm or rule out cross-reactivity between levofloxacin and other quinolones.Therefore, a joint study was designed between 2 allergy departments to assess cross-reactivity between levofloxacin and other quinolones.
  
  
  METHODS
  We studied 12 patients who had experienced an immediate-type reaction (4 anaphylaxis and 8 urticaria/angioedema) after oral administration of quinolones. The culprit drugs were as follows: ciprofloxacin (5), levofloxacin (4), levofloxacin plus moxifloxacin (1), moxifloxacin (1), and norfloxacin (1). Allergy was confirmed by skin tests and controlled oral challenge tests with different quinolones. The basophil activation test (BAT) was applied in 6 patients.
  
  
  RESULTS
  The skin tests were positive in 5 patients with levofloxacin (2), moxifloxacin (2), and ofloxacin (2). BAT was negative in all patients (6/6). Most of the ciprofloxacin-reactive patients (4/5) tolerated levofloxacin. Similarly, 3 of 4 levofloxacin-reactive patients tolerated ciprofloxacin. Patients who reacted to moxifloxacin and norfloxacin tolerated ciprofloxacin and levofloxacin.
  
  
  CONCLUSIONS
  Our results suggest that skin testing and BAT do not help to identify the culprit drug or predict cross-reactivity. Oral challenge testing is the only way to confirm tolerance to a quinolone before prescribing it as a safe alternative. Levofloxacin could be a safer alternative in cases of reaction to first-, second-, or fourth-generation quinolones.
authors.affiliation: Department of Allergy, Hospital San Pedro/San Millán, Logroño, Spain. tlobera@riojasalud.es
authors.forename: T
authors.initials: T
authors.lastname: Lobera
authors.forename: M T
authors.initials: MT
authors.lastname: Audícana
authors.forename: E
authors.initials: E
authors.lastname: Alarcón
authors.forename: N
authors.initials: N
authors.lastname: Longo
authors.forename: B
authors.initials: B
authors.lastname: Navarro
authors.forename: D
authors.initials: D
authors.lastname: Muñoz
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D001491:Basophils / Q000276:immunology; D003429:Cross Reactions; D004342:Drug Hypersensitivity / Q000209:etiology* / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000139:chemically induced* / Q000276:immunology; D064704:Levofloxacin; D008297:Male; D008875:Middle Aged; D015242:Ofloxacin / Q000009:adverse effects*; D015363:Quinolones / Q000009:adverse effects*; D012882:Skin Tests; D055815:Young Adult
chemical_list: D015363:Quinolones; D064704:Levofloxacin; D015242:Ofloxacin