Emergent Care / Stabilization:
Disseminated herpes simplex virus (HSV) in neonates is a potentially life-threatening condition with high morbidity and mortality. This condition requires supportive care in the neonatal intensive care unit with early administration of intravenous (IV) acyclovir. Prompt diagnosis and aggressive systemic antiviral therapy are keys to avoiding mortality or permanent sequelae.

Diagnosis Overview:
Neonatal HSV can be acquired via intrauterine, perinatal, or postnatal transmission, with perinatal transmission from the vaginal canal during birth being the most common. Neonatal HSV may be mucocutaneous or disseminated, and it can involve the central nervous system (CNS).

• Intrauterine HSV infection usually presents within 2 days of birth. It may be associated with prematurity and brain abnormalities (eg, microcephaly, chorioretinitis, cerebral abnormalities) and may resemble epidermolysis bullosa. It typically presents with scarring skin lesions, ophthalmologic findings, and neurologic involvement.
• A majority of newborns acquire the infection during the peripartum period. Newborns will present with vesicles at birth or within the first few days of life. Lethargy and fever are common findings.
• Neonatal HSV can also be acquired after birth (10% of cases). While usually transmitted from adult caregivers, neonatal HSV acquired after birth may also be transmitted to male newborns during out-of-hospital circumcision.

Risk factors:

• Neonates delivered by mothers who have had their first (primary) episode of HSV during gestation are at greatest risk for neonatal HSV.
• If active HSV infection is present at the time of delivery, or when there is risk for shedding, cesarean section should be performed, as there is an increased risk of transmission with vaginal delivery.
• Rupture of membranes for more than 4-6 hours before delivery increases the risk of transmission of HSV to the infant, even if delivered via cesarean section.
• The use of fetal scalp electrode monitoring during labor also increases the risk of transmission to the neonate, as it compromises the integrity of the mucocutaneous barriers.

Dermatologic manifestations of neonatal HSV may present as a widespread eruption of vesicles, pustules, and/or erosions. Constitutional symptoms often occur and commonly consist of fever and regional lymphadenopathy. Most patients in whom infection is recognized in a timely fashion and who receive appropriate therapy recover without adverse event, but progression to fatal disease can occur. Involvement of ocular mucosa can cause viral conjunctivitis or keratitis.

About 1 in 3 neonatal HSV infections presents with disseminated disease, a potentially life-threatening condition. It can cause encephalitis or have a sepsis-like presentation. There may be internal organ involvement, including the liver (viral hepatitis), lungs (pneumonitis), CNS (meningoencephalitis), heart (myocarditis), adrenal glands, bone marrow (neutropenia or thrombocytopenia), kidney, and gastrointestinal tract (necrotizing enterocolitis), or it may present as disseminated intravascular coagulation (DIC). Multiorgan failure is possible. Neurologic symptoms and pneumonitis can present prior to or after the development of skin lesions. Neonates with CNS involvement may have seizures.

For a discussion of HSV acquired by older infants or children, see herpes simplex virus.