Early-onset herpes simplex encephalitis type 1 triggered by COVID-19 disease: A case report

Coronavirus disease 2019 (COVID-19) causes a systemic inflammatory response and a temporary immunosuppression of hosts. Several reports have showed that reactivation of herpes simplex virus type 1 (HSV-1) is strongly associated with COVID-19. We present a case of a 66-year-old female, who developed HSV-1 encephalitis, showing impaired consciousness and typical MRI findings such as hyperintense lesions in the temporal lobe, insular cortices, bilateral medial frontal lobe on diffusion-weighted imaging, 7 days after the onset of COVID-19 symptoms. The number of cases of encephalitis in patients with COVID-19 is increasing. However, there has been limited reports of HSV-1 encephalitis following COVID-19, especially for cases with an interval of 7 days or less from the onset of COVID-19 symptoms to the onset of HSV-1 encephalitis. Our case highlights the importance of considering HSV-1 encephalitis in the differential when managing a patient with COVID-19-associated neurologic complications, even if it is in the early stages of COVID-19.