EAACI 2025: Evaluation of PEN-FAST for Cephalosporin and Non-Beta-Lactam Allergy Assessment

Introduction:

Incorrect antibiotic allergy labels can lead to unnecessary drug avoidance, increased healthcare costs, and rising antimicrobial resistance. The PEN-FAST tool is a validated clinical decision rule for identifying patients with low-risk penicillin allergy labels who may safely undergo direct drug provocation testing. Its applicability to cephalosporins is under review, and limited data exist for trimethoprim-sulfamethoxazole. However, its broader use for non-beta-lactam antibiotics remains uncertain.

Methods:

• This retrospective single-center study was conducted at the Department of Dermatology, University Hospital Heidelberg, Germany.
• Time frame: 2004–2024
• Participants: Patients with recorded cephalosporin or non-beta-lactam antibiotic allergy labels
• Evaluations performed:
  • Skin testing
  • Allergen-specific IgE testing
  • Drug provocation testing
• Definition of confirmed allergy: Positive result in any diagnostic modality
• Risk classification: PEN-FAST scoring system used to identify low-risk patients

Results:

Conclusion:

PEN-FAST showed high sensitivity in identifying true allergy across both cephalosporin and non-beta-lactam labels. Its strong NPV for cephalosporins supports its role in de-labeling low-risk patients. However, the lower NPV for non-beta-lactams suggests the tool’s performance may not be consistent across all antibiotic classes, indicating the need for further validation before broader application.

European Academy of Allergy and Clinical Immunology 2025,13-16 June, Glasgow, United Kingdom.