Utilization and timeliness of an inpatient penicillin allergy evaluation

Background: A history of penicillin allergy is associated with an increased risk of nosocomial infections because patients are exposed to non-beta lactam antibiotics. Ruling out inaccurate penicillin allergy during hospitalization decreases prescription of beta lactam antibiotics. However, the utilization of penicillin allergy testing and timeliness in relation to initiation of antibiotics is not known. Objective: Our aim was to describe the proportion and characteristics of patients who underwent inpatient penicillin allergy testing in a hospital without a guideline or infrastructure for inpatient penicillin allergy testing. Methods: We performed a retrospective chart review of patients admitted to our institution between January 1, 2008, and December 31, 2015, who underwent penicillin allergy testing. Results: Forty-nine patients were identified; 27 (55.1%) were women. The median age was 61.5 years (interquartile range [IQR], 48.5-71 years). The median Charlson-Comorbidity index score was 4 (IQR, 2-5.5). Of these patients, 42.86% (21) were admitted to the intensive care unit, 79.6% of allergy consults were requested by infectious disease physicians, and 87.8% of patients were receiving non-beta lactam antibiotics at the time of testing. The patients received a median of 5 days of antibiotics before testing (range, 0-16 days; IQR, 3-7 days). Antimicrobial therapy was changed in 78.0% of the patients (32), of whom 68.3% (21/32) was attributable to penicillin allergy testing. Conclusion: Inpatient penicillin allergy testing is a critical component of antibiotic stewardship; however, an adequate infrastructure is essential for timely evaluation. Inpatient penicillin allergy evaluation requires a multidisciplinary approach focused on patient selection; risk stratification; and optimization of a timely, safe, and cost-effective approach to optimize patient outcomes.