Herpes Simplex Encephalitis Treatment Guidelines

Diagnosis and Treatment Approach

The American Academy of Neurology recommends that all patients with suspected herpes simplex encephalitis should be started on intravenous acyclovir 10 mg/kg every 8 hours without waiting for diagnostic confirmation, and treatment should be continued for at least 21 days 1, 2
The Infectious Diseases Society of America suggests that treatment should be initiated within the first 6 hours of hospital admission, as delays of more than 48 hours are associated with poor prognosis 3, 4, 5
The Centers for Disease Control and Prevention recommend that diagnostic test results should not be waited for, and empirical treatment should be started in all patients with suspected encephalitis 2

The standard adult dose of acyclovir is 10 mg/kg IV every 8 hours, with a minimum treatment duration of 21 days 1, 2
The American Academy of Pediatrics recommends a higher dose of 20 mg/kg IV every 8 hours for 21 days in newborns 5

The Infectious Diseases Society of America recommends that all immunocompromised patients should undergo the following tests: CSF PCR for HSV 1 & 2, VZV, enteroviruses, EBV, and CMV, as well as CSF and blood cultures for Listeria monocytogenes and Cryptococcus neoformans 1
The Centers for Disease Control and Prevention suggest that immunocompromised patients with encephalitis should be treated with intravenous acyclovir 10 mg/kg every 8 hours for at least 21 days, with consideration for longer treatment duration in patients with persistent viral load 1, 5

The Infectious Diseases Society of America recommends that varicella-zoster virus encephalitis should be treated with intravenous acyclovir 500 mg/m² for at least 10 days, with consideration for longer treatment duration in immunocompromised children 1, 5
The American Society of Transplantation suggests that cytomegalovirus infection should be treated with ganciclovir plus foscarnet, or alternatively with oral valganciclovir 1, 2

The American Academy of Neurology recommends that patients with herpes simplex encephalitis should be monitored for prognostic factors, including age, Glasgow coma score, and treatment delay, as these factors are associated with poor outcomes 3, 4
The Infectious Diseases Society of America suggests that untreated herpes simplex encephalitis is associated with a mortality rate of up to 70%, but early treatment with acyclovir can reduce this rate to 25-28% 4