Can COVID-19 Increase the Risk of Herpes Zoster? A Narrative Review

Abstract

Herpes zoster (HZ) is associated with substantial morbidity. It is caused by reactivation of the latent varicella zoster virus (VZV) following decline in cell-mediated immunity, which is commonly age-related, but also occurs in individuals with immunosuppressive diseases and/or treatment. Since coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has been associated with T cell immune dysfunction and there have been reports of HZ in COVID-19 patients, we have performed a review of available literature on whether COVID-19 could trigger HZ. We identified 27 cases of HZ following COVID-19, which most frequently occurred within 1-2 weeks of COVID-19, and the majority of cases had typical presentation. Atypical presentations of HZ were noted especially in patients with lymphopenia. It has been hypothesized that VZV reactivation occurs as a consequence of T cell dysfunction (including lymphopenia and lymphocyte exhaustion) in COVID-19 patients. Based on current evidence, which is limited to case reports and case series, it is not possible to determine whether COVID-19 increases the risk of HZ. Practitioners should be aware of the possible increased risk of HZ during the pandemic period and consider timely therapeutic and preventive measures against it.

Keywords: COVID-19; Cell-mediated immunity; Herpes zoster; Lymphopenia; SARS-CoV-2; Shingles.

Fig. 1

Period until HZ diagnosis following COVID-19 (N = 23) [–15, 17]

Fig. 2

Average per million inhabitants with herpes zoster (HZ) diagnoses reported by the Brazilian public health system in all geographical regions between March and August 2017–2019 compared to the same period in 2020 [30]