Characteristics of herpes zoster infection in patients with COVID-19: a systematic scoping review

Background Although there is literature reporting correlations between varicella zoster virus (VZV) infections and COVID-19, insufficient evidence exists in this regard. This scoping review aims to identify the existing evidence regarding clinical characteristics of primary VZV infection or reactivation in COVID-19. Methods Following the PRISMA Extension for Scoping Reviews, MEDLINE and EMBASE were searched for all peer-reviewed articles with relevant keywords including "Zoster," "Herpes," and "COVID-19" from their inception to November 20, 2021. Results A total of 19 articles with three observational studies and 16 case reports or series were included. Primary VZV infections or reactivation were observed in 25 patients. Forty-eight percent of the patients had disseminated VZV infection. The median time of VZV-related rash after the onset of respiratory symptoms was 7.0 days (interquartile range: 0-18.8). Those with COVID-19 and primary VZV infection or reactivation had low lymphocyte counts with a median of 0.67 x 10(3)/mu l. Conclusion This scoping review identified uncertainty and a lack of strong evidence to see the association between primary VZV infection or reactivation and COVID-19. However, those with COVID-19 may be more likely to have disseminated VZV, which poses an additional challenge from an infection prevention standpoint. Future studies are warranted to determine the association between primary VZV infection or reactivation and long-term consequences related to COVID-19.