Diagnostic Dilemmas: A Review of Reported Cases of Human Herpesvirus-6 Encephalitis in Immunocompetent Adults

Abstract

Human Herpesvirus 6 (HHV-6) is associated with its presentation in the paediatric population as roseola infantum. Rarely, it is the causative agent of encephalitis, with most cases reported amongst the immunocompromised population due to reactivation. This review article analyses the available literature records of cases labelled as HHV-6 encephalitis in immunocompetent adults, aiming to understand the diagnostic methods behind each case and explore the complexities of such a diagnosis. We note significant variability in the methods used to come to a diagnosis of HHV-6 encephalitis, as well as inconsistent approaches to treatment of this condition. Given the rarity of HHV-6 encephalitis in immunocompetent adults, there are no clearly structured diagnostic guidelines for this condition in this patient population. We highlight several diagnostic methods that provide more convincing evidence of true HHV-6 encephalitis and may provide a basis for further development of guidelines for the diagnosis and treatment of this condition.