A tale of concealed source and bizarre CSF in an immunocompetent HSV2 Encephalitis patient

<p><strong>Background:</strong> HSV2 associated encephalitis is a rare occurrence, described in neonates and immunocompromised individuals.</p> <p><strong>Case presentation:</strong> We describe a case of HSV-2 associated encephalitis associated with genital herpetic lesions. MRI brain showed large confluent T2/FLAIR hyperintensities involving left medial temporal lobe, left insula and left anterior cingulate gyrus. LP-CSF showed presence of marked neutrophilic leucocytosis mimicking  a pyogenic meningo-encephalitis etiology. CSF biofire ME test (Film Array Multiplex PCR based Meningoencephalitis panel) was positive for HSV-2.  The patient was treated with IV acyclovir for 14 days and subsequent to improvement in symptoms was discharged. In view of recurrence of symptoms he required readmission and was given a further 14 day course of IV Acyclovir and subsequent to normalization of CSF parameters was discharged. Our patient required prolonged course of IV acyclovir of more than 3 weeks.</p> <p><strong>Conclusion:</strong> This case serves to highlight that treatment in HSV-2 encephalitis may need to be prolonged if the patient is not having resolution of symptoms or acellularity in CSF/ negative PCR report has not been achieved.   </p>