What is the most appropriate management for a neonate born to a mother who developed a fever and vesicular rash, suggestive of varicella (chickenpox), 2 days prior to delivery, with the rash becoming intensely pruritic on the day of delivery?

From the Guidelines

The most appropriate management of this neonate is to administer varicella immune globulin (option B). This neonate was born to a mother with active varicella infection, as evidenced by her fever and vesicular rash that began shortly before delivery. When a mother develops varicella within 5 days before or 2 days after delivery, the neonate is at high risk for severe neonatal varicella due to insufficient time for maternal antibody transfer, as noted in the study by 1. Varicella immune globulin (VZIG) should be administered as soon as possible, ideally within 96 hours of birth, to provide passive immunity. The dose is 125 units/10 kg body weight given intramuscularly. For this 2.95 kg neonate, approximately 37 units would be appropriate. VZIG can prevent or modify the severity of neonatal varicella infection. Some key points to consider in the management of this neonate include:

• The risk of severe varicella infection in neonates born to mothers who develop varicella within 5 days before or 2 days after delivery is estimated to be 17%-30% 1.
• The risk of neonatal death in such cases has been estimated to be 31% among infants whose mothers had onset of rash <4 days before giving birth 1.
• Varicella-zoster immune globulin (VZIG) has been reported to reduce the incidence of severe neonatal varicella disease 1. The neonate should also be isolated from the mother until her lesions have crusted over, and from other infants to prevent nosocomial spread. Antiviral therapy is not routinely recommended prophylactically but would be indicated if the infant develops clinical varicella despite VZIG. Vaccination is contraindicated in neonates, and serum IgG testing or observation alone would be insufficient management given the high risk of severe disease in this clinical scenario.

From the FDA Drug Label

Special Populations : Pediatrics:In general, the pharmacokinetics of acyclovir in pediatric patients is similar to that of adults. Chickenpox:Three randomized, double-blind, placebo-controlled trials were conducted in 993 pediatric patients aged 2 to 18 years with chickenpox.

The most appropriate management of this neonate is to Administer varicella immune globulin or Recommend isolation and close observation alone but since the mother has varicella (chickenpox), the neonate is at high risk, and varicella immune globulin would be more appropriate, however the provided label does not directly answer the question for a neonate, but based on the information that varicella immune globulin is used for post-exposure prophylaxis, the answer would be B. Administer varicella immune globulin 2.

From the Research

Management of Varicella in Neonates

The management of varicella in neonates depends on various factors, including the timing of exposure, maternal immunological status, and the baby's gestational age.

• The neonate in question was born to a mother who developed a fever 2 days ago and a vesicular rash on her face and chest yesterday, which spread to her abdomen and became intensely pruritic on the day of delivery 3, 4.
• Given that the mother's rash appeared within 2 days of delivery, the neonate is at high risk for varicella complications.
• According to the studies, varicella zoster immune globulin (VARIZIG) is recommended for postexposure prophylaxis in high-risk individuals, including neonates whose mothers had varicella onset within 5 days before or 2 days after delivery 3, 4.
• The administration of VARIZIG within 96 hours of exposure can help prevent or attenuate varicella-zoster virus infection in high-risk individuals 4.
• In this case, the most appropriate management of the neonate would be to administer varicella immune globulin, as the neonate is at high risk for varicella complications due to the timing of the mother's rash appearance.

Treatment Options

• Administering antiviral therapy may not be necessary in this case, as the neonate is not showing any symptoms of varicella and the administration of VARIZIG can help prevent the infection 5, 6.
• Varicella vaccination is not recommended for neonates, as it is not effective in preventing varicella in this age group 5, 6.
• Obtaining serum varicella IgG may not be necessary, as the neonate's risk of varicella complications is already established due to the mother's rash appearance within 2 days of delivery 3, 4.
• Isolation and close observation alone may not be sufficient, as the neonate is at high risk for varicella complications and requires proactive management to prevent or attenuate the infection 3, 4.