Increased Risk of Herpes Zoster in Adults ≥50 Years Old Diagnosed With COVID-19 in the United States.

Background: Case reports have described herpes zoster (HZ) in patients with coronavirus disease 2019 (COVID-19). However, this constitutes low-quality evidence for an association. We therefore performed a retrospective cohort study to assess the risk of developing HZ following a COVID-19 diagnosis. Methods: We compared the HZ incidence in ≥50-year-olds diagnosed with COVID-19 vs those never diagnosed with COVID-19. We used data from the US MarketScan Commercial Claims and Encounters and Medicare Supplemental (3/2020-2/2021) and Optum Clinformatics Data Mart (3-12/2020) databases. Individuals with COVID-19 were exact-matched 1:4 to those without COVID-19 by age, sex, presence of HZ risk factors, and health care cost level. Adjusted incidence rate ratios (aIRRs) were estimated by Poisson regression. Results: A total of 394 677 individuals ≥50 years old with COVID-19 were matched with 1 577 346 individuals without COVID-19. Mean follow-up time after COVID-19 diagnosis and baseline characteristics were balanced between cohorts. Individuals diagnosed with COVID-19 had a 15% higher HZ risk than those without COVID-19 (aIRR, 1.15; 95% CI, 1.07-1.24; P < .001). The increased HZ risk was more pronounced (21%) following COVID-19 hospitalization (aIRR, 1.21; 95% CI, 1.03-1.41; P = .02). Conclusions: We found that COVID-19 diagnosis in ≥50-year-olds was associated with a significantly increased risk of developing HZ, highlighting the relevance of maintaining HZ vaccination.

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

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.