Pediatric Guidelines: Viral Infections - Herpes Simplex Virus

Condition Major Pathogens First Choice Therapy Alternative Therapy Comments

Neonatal herpes simplex

Consider diagnosis in infants < 6 weeks old with cutaneous vesicles, seizure, focal neurologic signs, CSF pleocytosis with non-bacterial profile, thrombocytopenia or hepatitis

Herpes simplex virus Acyclovir 20mg/kg/dose IV q8h  

ID consult recommended

Full evaluation with LP, CSF HSV PCR, blood HSV PCR and surface cultures is recommended for all forms of neonatal HSV disease

Suppressive therapy with oral acyclovir 300mg/m2/dose PO q8h is now recommended for all forms of neonatal HSV disease, for at least 6 months after treatment course completed - consult Pediatric ID for guidance on duration and monitoring

Herpes simplex encephalitis or other disseminated disease (non-neonatal) Herpes simplex virus

Age 3 months to < 12 years:

Acyclovir 10-15mg/kg/dose IV q8h

  ID consult recommended

Age >=12 years:

Acyclovir 10mg/kg/dose IV q8h

Herpes simplex, mucocutaneous (non-neonatal) Herpes simplex virus

IV therapy:


Acyclovir 5-10mg/kg/dose IV q8h

Oral therapy preferred if feasible due to lower risk for nephrotoxicity

Oral therapy:

Acyclovir 20mg/kg/dose (max 400mg/dose) PO TID


Valacyclovir 20mg/kg/dose (max 1000mg/dose) PO BID

Treatment most likely to be beneficial if initiated within 72 hours of onset. 

Duration: Dependent on clinical resolution, generally 5-7 days


Acyclovir 10mg/kg/dose IV q8h 

These are guidelines only and not intended to replace clinical judgment. Modification of therapy may be indicated based on patient comorbidities, previous antibiotic therapy or infection history. Doses provided are usual doses but may require modification based on patient age or comorbid conditions. Refer to Pediatric Antimicrobial Dosing Guideline for further guidance on dosing in children, and Neonatal Dosing Guideline for infants < 1 month of age. Consult a pediatric pharmacist for individualized renal or hepatic dose adjustment. For additional guidance, please contact Pediatric Infectious Diseases (ID) or the Pediatric Antimicrobial Stewardship Program (ASP).