What is the first step in managing a newborn with a reddish rash and vesicles, born to a Group B Streptococcus (GBS)-negative mother with a history of Herpes Simplex Virus (HSV) infection, who received antiviral therapy with Acyclovir (acyclovir) for 36 weeks?

From the Guidelines

The first step in management for this newborn with a reddish rash with vesicles that rupture easily and leave behind a small rosette is acyclovir treatment plus HSV swab (option A). Given the maternal history of HSV and the characteristic vesicular rash in the newborn, there is high suspicion for neonatal herpes infection despite the mother's antiviral therapy during pregnancy and absence of visible lesions at delivery 1. Immediate empiric treatment with intravenous acyclovir (typically 20 mg/kg/dose every 8 hours) should be initiated while simultaneously obtaining vesicle fluid samples for HSV PCR testing to confirm the diagnosis. According to the most recent guidelines, acyclovir is the drug of choice for treatment of HSV among infants and children, regardless of HIV-infection status 1. Neonatal herpes is a medical emergency with significant morbidity and mortality if treatment is delayed. Even with maternal antiviral prophylaxis, transmission can still occur, particularly if there is asymptomatic viral shedding at delivery. The vesicular rash with rosette pattern is highly suggestive of HSV infection rather than bacterial infection or a benign dermatologic condition, making immediate antiviral therapy the appropriate first step while awaiting confirmatory testing.

Key considerations in this case include:

• The high risk of transmission of HSV to the neonate, even with maternal antiviral therapy during pregnancy 1
• The importance of prompt empiric treatment with acyclovir to reduce morbidity and mortality 1
• The need for simultaneous diagnostic testing, such as HSV PCR, to confirm the diagnosis
• The potential for significant neurologic sequelae in infants with neonatal HSV infection, despite successful treatment 1

From the FDA Drug Label

Neonatal Herpes Simplex Virus Infection Acyclovir for Injection is indicated for the treatment of neonatal herpes infections. The first step in management is to start the baby on acyclovir as the drug label indicates that acyclovir is used to treat neonatal herpes simplex virus infection 2.

• The presence of a reddish rash with vesicles that rupture easily and leave behind a small rosette is suggestive of a herpes simplex infection.
• Given the clinical presentation, HSV swab should also be performed to confirm the diagnosis. Therefore, the correct answer is a) Acyclovir + HSV swab 2.

From the Research

Management of Neonatal Herpes Simplex Virus Infection

The first step in managing a neonate with suspected herpes simplex virus (HSV) infection is to initiate empiric acyclovir therapy, as the infection can be difficult to diagnose and has high morbidity and mortality rates 3, 4.

• The presentation of a reddish rash with vesicles that rupture easily and leave behind a small rosette is consistent with neonatal HSV infection, which can be categorized into localized skin, eyes, or mouth; localized central nervous system; or disseminated infections 3, 5.
• Parenteral acyclovir is the pharmacologic agent of choice for treating neonatal HSV infections, and dosage strategies and durations of therapy may vary based on disease state severity, presentation, and patient characteristics 3.
• Empiric acyclovir therapy is often started in neonates with suspicious skin lesions, seizures, or hemodynamic instability, and it is essential to consider the diagnosis of neonatal HSV infection in these cases 4.
• In addition to acyclovir therapy, obtaining a surface swab for HSV and performing other diagnostic tests, such as cerebrospinal fluid analysis, can help confirm the diagnosis and guide management 4, 6.

Diagnostic Considerations

• A surface swab for HSV can be performed to help diagnose neonatal HSV infection, and acyclovir therapy can be initiated empirically while awaiting test results 4, 6.
• The diagnosis of neonatal HSV infection can be challenging, and clinicians should consider the diagnosis in neonates with suspicious skin lesions, seizures, or hemodynamic instability, even if the mother is GBS-negative and has a distant history of HSV 4, 7.