Improving the Effectiveness of Penicillin Allergy De-labeling

Area of Science:

• Clinical Immunology
• Pharmacology
• Allergy Diagnostics

Background:

• Up to 20% of hospitalized patients are labeled penicillin-allergic, incurring significant healthcare costs.
• Accurate penicillin allergy assessment is crucial for appropriate antibiotic selection and reducing adverse drug events.

Purpose of the Study:

• To evaluate the effectiveness of penicillin allergy de-labeling in clinical practice.
• To develop risk stratification models for guiding penicillin allergy testing strategies.

Main Methods:

• A study of 401 patients aged 15+ with beta-lactam allergy referred for drug allergy assessment.
• Inclusion of skin prick testing (SPT), intradermal testing (IDT), and oral challenge (OC) for penicillin allergy evaluation.
• Follow-up surveys assessed antibiotic usage and adherence to allergy label modifications (ALM).

Main Results:

• 12.3% of patients tested positive to penicillin reagents, with higher rates in immediate (30.4%) versus non-immediate (3.1%) reaction groups.
• Oral challenge (OC) had a 99.2% negative predictive value, with only 0.8% experiencing non-serious reactions.
• Beta-lactam antibiotic recommendations were made for nearly 90% of patients, with higher adherence in the non-immediate reaction group.

Conclusions:

• Penicillin skin testing, intradermal testing, and oral challenge safely de-label patients and identify specific beta-lactam allergies.
• Incomplete adherence to allergy label modifications impacts the effectiveness of de-labeling.
• For non-immediate reactions, oral challenge alone may be a safe, cost-effective de-labeling strategy, potentially increasing coverage.