A statement on cefazolin immediate hypersensitivity: data from a large database, and focus on the cross-reactivities.

Area of Science:

• Immunology
• Pharmacology
• Clinical Medicine

Background:

• Increased use of cefazolin has led to a rise in cefazolin-associated hypersensitivity reactions.
• Understanding these reactions is crucial for patient safety and effective antibiotic prescribing.

Purpose of the Study:

• To investigate immediate hypersensitivity reactions to cefazolin.
• To assess potential allergic cross-reactivity between cefazolin and other beta-lactam antibiotics.

Main Methods:

• Review of 25 cefazolin-associated reactions from the Drug Allergy and Hypersensitivity Database (DAHD).
• Investigation of cases using skin testing and drug challenges per European Network for Drug Allergy (ENDA) guidelines.

Main Results:

• Ten individuals with confirmed IgE-mediated cefazolin hypersensitivity were identified.
• Reactions included anaphylaxis, systemic allergic reactions, and urticaria/angioedema.
• Seven patients had positive cefazolin skin tests, and three had positive challenges. Crucially, eight cefazolin-allergic patients tolerated other beta-lactams in challenges.

Conclusions:

• A majority of patients with IgE-mediated cefazolin allergy tolerated amoxicillin and some cephalosporins.
• The R1 side-chain of cefazolin appears significant in eliciting IgE-mediated reactions.
• Predicting cross-reactivity with other beta-lactams requires further research.