Flucloxacillin Hypersensitivity: Patient Outcomes in a Multicenter Retrospective Study.

Abstract

BACKGROUND:

Flucloxacillin is a narrow-spectrum, beta-lactamase-resistant penicillin. Type I (IgE-mediated) and type IV (T-cell-mediated) reactions are less frequently reported than with other penicillins.

OBJECTIVE:

To undertake a detailed clinical characterization of a cohort of patients referred with suspected flucloxacillin hypersensitivity.

METHODS:

We retrospectively analyzed demographic characteristics, presentation, investigation, and management of 108 patients presenting to 4 UK centers. Patients underwent skin prick and intradermal testing with flucloxacillin, major (benzylpenicilloyl poly-l-lysine) and minor determinants, amoxicillin, and benzylpenicillin with immediate and, where appropriate, delayed reading of the test. In the immediate group, a further 14 patients were tested to ampicillin and 16 to Augmentin (co-amoxiclav-combination of clavulanic acid and amoxicillin). Skin test-negative patients underwent oral drug provocation. A multistep protocol was used, depending on risk assessment.

RESULTS:

Forty of 108 (37%) patients were diagnosed with hypersensitivity to flucloxacillin, of whom 33 (82.5%) showed immediate and 7 (17.5%) nonimmediate hypersensitivity, respectively. In the immediate group, most reactions were severe: 19 of 33 (58%). Intradermal testing had a higher negative predictive value (86%) in the immediate group than in the nonimmediate group (67%). Only a minority of patients (6 of 17 [35%]) with IgE-mediated allergy were cross-sensitized on intradermal testing with other penicillins, compared with 3 of 4 (75%) in the delayed group.

CONCLUSIONS:

Immediate hypersensitivity reactions to flucloxacillin are more common than delayed. Cross-sensitization to other penicillins appears higher in delayed reactions than in immediate. The negative predictive value of intradermal testing is higher in the immediate group than in the nonimmediate group. Drug provocation testing remains the diagnostic criterion standard.

• Authors: Lucinda Kennard, Krzysztof Rutkowski, Leonard Q C Siew, Alla Nakonechna, Ravishankar Sargur, William Egner, Anna Shrimpton, Rita Mirakian, Annette Wagner
• Journal: The journal of allergy and clinical immunology. In practice (J Allergy Clin Immunol Pract) 2019 Sep - Oct Vol. 7 Issue 7 Pg. 2212-2217.e1 ISSN: 2213-2201 [Electronic] United States
• PMID: 30922988 (Publication Type: Journal Article, Multicenter Study)
• Copyright: Copyright © 2019 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Chemical References

• Anti-Bacterial Agents
• Immunoglobulin E
• Floxacillin
• Amoxicillin-Potassium Clavulanate Combination
• Amoxicillin
• Tryptases
• Penicillin G

Topics

• Adult
• Aged
• Aged, 80 and over
• Amoxicillin
• Amoxicillin-Potassium Clavulanate Combination
• Anti-Bacterial Agents (adverse effects)
• Cross Reactions
• Drug Eruptions (diagnosis, etiology)
• Drug Hypersensitivity (diagnosis, etiology, metabolism)
• Drug Hypersensitivity Syndrome (diagnosis, etiology)
• Female
• Floxacillin (adverse effects)
• Humans
• Hypersensitivity, Delayed (chemically induced, diagnosis, metabolism)
• Hypersensitivity, Immediate (chemically induced, diagnosis, metabolism)
• Immunoglobulin E (metabolism)
• Intradermal Tests
• Male
• Middle Aged
• Penicillin G
• Predictive Value of Tests
• Referral and Consultation
• Retrospective Studies
• Skin Tests
• Tryptases (metabolism)
• Young Adult