Cephalosporin Allergy Evaluation Improves Antibiotic Stewardship in Immunocompromised Inpatients

A targeted inpatient allergy consult service employing risk stratification and drug provocation testing significantly improved antibiotic stewardship by safely de-labeling cephalosporin allergies in immunocompromised patients, according to results of a recent study presented at the American College of Allergy, Asthma & Immunology 2025 Annual Scientific Meeting.

The study evaluated 33 cephalosporin challenges conducted between August 2021 and July 2024 at a tertiary care center. All patients had at least one immunocompromising condition. Challenges were administered as either full-dose (51.5%) or 10/90 (48.5%) protocols based on risk stratification. Drug selection considered allergy history and R1 side chain similarity.

Of the 33 challenges, 93.9% were negative, indicating no adverse reaction to the cephalosporin administered. Challenges directly addressed the listed allergy label in 60.6% of cases, used a cephalosporin with a similar R1 side chain in 12.1%, and a different R1 side chain in 27.3%.

Notably, 39.4% of patients were treated with a cephalosporin that had previously been restricted due to the allergy label during their current admission. Additionally, 42.4% received such treatment in subsequent hospitalizations or outpatient care.

The investigators noted that “57.6% of patients had a history of antibiotic resistance,” highlighting the clinical relevance of accurate allergy assessment in this population. Broad-spectrum antibiotic use is often the default for patients labeled with beta-lactam allergies, contributing to resistance and suboptimal treatment.

The findings support incorporating medication history review and direct oral challenges into routine inpatient allergy evaluation. The authors concluded, “A risk stratification approach incorporating medication history review and challenges can safely evaluate inpatient cephalosporin allergy labels in immunocompromised patients, resulting in improved antibiotic stewardship.”

These results underscore the importance of formal allergy testing to guide appropriate antibiotic selection and reduce unnecessary broad-spectrum antibiotic exposure.

Reference
Antibiotic outcomes of cephalosporin allergy evaluation in the immunocompromised inpatient population. Presented at: American College of Allergy, Asthma & Immunology 2025 Annual Scientific Meeting; November 6-10, 2025; Orlando, FL.