A CALL TO ACTION FOR PENICILLIN ALLERGY DELABELING IN PATIENTS WITH SYPHILIS

Abstract

Introduction

The number of people with untreated syphilis in the United States is at its highest since the 1950s. Penicillin, the first-line treatment for syphilis, may be avoided in those labeled as penicillin allergic, thus fueling the public health crisis, risk of congenital syphilis, individual morbidity, and excessive healthcare utilization.

Methods

We retrospectively reviewed penicillin allergy labeled patients with confirmed syphilis referred to our drug allergy clinic for assessment and delabeling from January 2014 to January 2024. We collected data on demographics, syphilis stage, results of penicillin allergy testing, use of second-line treatment, healthcare utilization and use of penicillin after delabeling, and clearance of syphilis.

Results

Of 12 patients identified, 83.3% were male and the median age was 39. Prior to our evaluation, 9 patients were treated with doxycycline, some multiple times (5 successful and 7 failed treatments total). One ceftriaxone-treated patient failed treatment. Three patients were desensitized to penicillin in the ICU. One female patient treated with penicillin desensitization had a pregnancy complicated by congenital syphilis. 12/12 patients were ultimately delabeled of their penicillin allergy. 9/12 had documented subsequent penicillin treatment, while 3/12 had incomplete/lost follow up in our EHR. Of the 9 who received penicillin, 5 had clearance, 3 had failed clearance (2 reinfection, 1 unknown reasons), and 1 had unknown clearance outcome.

Conclusion

Syphilis is an individual and public health emergency. We have shown that most patients labeled as penicillin allergic that are low risk should be aggressively delabeled to avoid treatment failure, increased healthcare utilization, and negative public health consequences.