Management of Beta-Lactam Antibiotics Allergy: A Real-Life Study

Area of Science:

• Clinical Immunology
• Infectious Diseases
• Antimicrobial Stewardship

Background:

• Beta-lactam allergy is a prevalent clinical issue, frequently leading to unnecessary avoidance of these crucial antibiotics.
• This avoidance contributes to increased healthcare costs, adverse effects, and the rise of antimicrobial resistance.
• Delabeling beta-lactam allergy is a key component of effective antimicrobial stewardship programs.

Purpose of the Study:

• To evaluate the frequency of confirmed immediate and delayed hypersensitivity to beta-lactam antibiotics (penicillin, cephalosporin).
• To determine the negative predictive value (NPV) and sensitivity of skin tests for beta-lactam allergy.
• To assess the safety of skin testing and drug challenges in patients with a beta-lactam allergy label.

Main Methods:

• Retrospective analysis of 576 patients referred for beta-lactam allergy evaluation.
• Systematic investigation using a standardized algorithm including skin tests and drug challenges.
• Assessment of immediate- and delayed-type hypersensitivity reactions to penicillin and cephalosporin subclasses.

Main Results:

• Only 18.3% of patients (63 immediate, 23 delayed) had confirmed beta-lactam allergy.
• Penicillin allergy was most frequent (65 patients), followed by cephalosporins (21 patients).
• High NPV for skin tests (96.3-100% for immediate, 87.5-91.9% for delayed) and low rates of adverse events (0.7% skin tests, 3.1% drug challenges) were observed.

Conclusions:

• The majority of patients labeled with beta-lactam allergy do not have a confirmed hypersensitivity.
• Standardized allergic workup, including skin tests and drug challenges, is safe and effective for delabeling.
• Accurate allergy assessment supports appropriate antibiotic selection and conserves second-line agents.