Disseminated herpes zoster with acute encephalitis in an immunocompetent elderly man.

Varicella-zoster virus (VZV) encephalitis typically occurs in immunosuppressed populations such as in patients with HIV/AIDS, transplantation and autoimmune disease. However, it can also occur in healthy hosts. We present the case of an immunocompetent patient who presented with a clinical picture of VZV encephalitis with the sole precipitating factor of advanced age. We want to stress the importance of including VZV in the differential diagnosis for encephalitis in healthy elderly hosts. In patients with a clinical diagnosis of encephalitis, the presence of herpes zoster rash increases the likelihood of VZV encephalitis. However, the absence of a skin rash may not exclude the diagnosis. In general, there is an elevated risk of transient ischaemic attack and stroke associated with the diagnosis of herpes zoster infection. Early treatment is essential to prevent complications, including death. © BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.