# Herpes zoster prevalence following epidural steroid injections: a retrospective review

## TL;DR

This study examines the low prevalence of shingles after epidural steroid injections and identifies risk factors like immunocompromised status and incomplete vaccination.

## Contribution

The study provides a retrospective analysis of shingles cases following epidural steroid injections in a large patient cohort.

## Key findings

- Out of 50,270 injections, only 37 patients developed shingles within 31 days.
- Most patients with shingles were over 70 years old and had immunocompromised or incomplete vaccination status.
- The study found no strong evidence of a direct causal link between epidural steroid injections and shingles.

## Abstract

Herpes Zoster, or shingles, is an infection caused by the reactivation of the latent Varicella zoster virus within a sensory ganglion, leading to painful skin lesions localized along dermatomes. Patients undergoing pain medicine procedures involving steroids may face an elevated risk of shingles, which can significantly impact their quality of life. Though rare, HZ has been reported following minimally invasive procedures, such as epidural steroid injections.

We evaluated the prevalence of shingles within 31 days after epidural steroid injections within Mayo Enterprise sites.

A retrospective chart review included all patients who reported a new HZ event within 31 days after receiving an epidural steroid injection. Information on patient demographics, procedure details, and potential risk factors for herpes zoster was assessed using qualitative analysis.

A total of 50,270 epidural injections were performed during the analyzed period. After initial screening, 149 patients were included for chart review, and 37 individuals met the inclusion criteria. Within this subgroup, the median age was 72, and 21 patients were female (56.76 %). The mean timeframe from the procedure until onset of symptoms of infection as reported in the medical record was 15.9 days. Among the patients in the study, 24 patients (64.86 %) had an identified immunocompromised status, and 28 (75.68 %) had an incomplete vaccination status at the time of infection.

The incidence of HZ following ESI is low. Other risk factors linked to HZ were identified in our cohort, confounding a possible causal relationship. Prospective studies are needed to elucidate any relationship between ESI and HZ.