Penicillin allergy: a practical approach to assessment and prescribing

Area of Science:

• Allergy and Immunology
• Clinical Medicine
• Pharmacology

Background:

• Penicillin allergy is a common concern, often leading to avoidance of crucial antibiotics.
• Many patients labeled with penicillin allergy may not be truly allergic, impacting treatment options.

Purpose of the Study:

• To evaluate the persistence and characteristics of penicillin allergies.
• To identify patient subgroups suitable for allergy reassessment and potential delabeling.

Main Methods:

• Review of clinical data on patients with reported penicillin allergies.
• Analysis of allergy persistence rates over time (approximately five years).
• Assessment of cross-reactivity with cephalosporins and criteria for oral penicillin rechallenge.

Main Results:

• Approximately 50% of penicillin allergies resolve within five years.
• Childhood reactions are frequently not indicative of true penicillin allergy.
• Only 1-2% of penicillin-allergic patients exhibit cephalosporin allergy; cephalosporins are safe for low-risk individuals.
• Delayed, non-severe reactions (e.g., mild rashes >10 years ago) may allow for supervised low-dose penicillin rechallenge.

Conclusions:

• Penicillin allergy is often not a lifelong condition, with significant rates of resolution.
• Appropriate assessment and testing can lead to the removal of the penicillin allergy label for many patients.
• Reassessment strategies, including supervised rechallenge, can safely expand antibiotic choices.