- A 2-day-old, term neonate discharged at 24 hours of age is brought into the emergency department because the mother has developed a vescicular rash . The infant is afebrile and has normal vital signs for age. Findings on physical examination are unremarkable
- Of the following, the BEST next step in the management of this patient is to administer
A. immune globulin intravenous
B. oral acyclovir
C. parenteral foscarnet
D. varicella vaccine
E. varicella-zoster immune globulin
- The mother of the neonate described in the vignette has a rash due to the varicella-zoster virus (VZV; ie, chickenpox), and the infant is at risk for serious, potentially fatal (25%) infection. The best next step in the management of the neonate is to administer varicella-zoster immune globulin intramuscularly, ideally within 96 hours (but indicated up to 10 days) after exposure. Varicella-zoster immune globulin is a purified human immune globulin preparation that contains high levels of antibodies against varicella. It was approved by the US Food and Drug Administration in 2012 for varicella prophylaxis in people at high risk for severe varicella who are not eligible to get the vaccine. Varicella-zoster immune globulin is preferred over intravenous immunoglobulin (IGIV) because clinical data demonstrating effectiveness of IGIV for varicella postexposure prophylaxis are lacking. However, IGIV may be used for postexposure prophylaxis if varicella-zoster immune globulin is unavailable.
For infants born to mothers who develop VZV infection 5 days before to 2 days after delivery, there is insufficient time for the production and transplacental transfer of VZV-specific maternal IgG to the infant. In addition, the neonate’s cellular immune system is immature, further increasing the risk of severe infection. Administration of varicella-zoster immune globulin within the 96-hour timeframe may be successful in preventing, ameliorating, or delaying varicella disease.
Varicella-zoster immune globulin for postexposure pro-phylaxis is recommended for the following high-risk individuals who have significant exposure to varicella and who cannot be immunized:
• Neonates born to mothers who develop chickenpox within 5 days before and 48 hours after delivery
• Neonates at greater than 28 weeks’ gestation whose mothers lack evidence of immunity
• Neonates at less than 28 weeks’ gestation or weighing less than 1000 g in birth weight regardless of maternal immunity
• Pregnant women without evidence of immunity
• Immunocompromised persons without evidence of immunity
Other people without evidence of varicella immunity in whom varicella-zoster immune globulin may be used for postexposure prophylaxis include household contacts, play-mates with significant contact, close hospital contacts, and those with intimate contact with a contagious person with varicella or zoster.
There are limited data on the use of acyclovir for post-exposure prophylaxis against varicella in healthy children. Some experts recommend the administration of prophylactic acyclovir if varicella-zoster immune globulin or IGIV is unavailable or not administered within 96 hours of exposure. Parenteral foscarnet is used almost exclusively in immunocompromised hosts with infections caused by acyclovir-resistant VZV. Varicella vaccine is recommended for postexposure prophylaxis for healthy people without evidence of immunity 12 months or older. The vaccine may prevent or ameliorate disease if administered within 72 (some data support up to 120) hours after exposure to varicella
- Varicella vaccine should not be administered to people with congenital or acquired T-cell immunodeficiency, including those with leukemia, lymphoma, other malignant tumors that affect the bone marrow or lymphatics, human immunodeficiency virus infection with a CD4+ T-lymphocyte percentage less than 15%, and long-term immune suppression, including high-dose (2 mg/kg of prednisone) systemic steroid use for more than 2 weeks. Varicella vaccine also should not be administered to pregnant women or those with a life-threatening reaction to any component of the vaccine.
Intramuscular varicella-zoster immune globulin (within 96 hours after exposure) is recommended for high-risk individuals who have significant exposure to varicella and who cannot be immunized.
Varicella vaccine (72-120 hours after exposure) is recommended for postexposure prophylaxis for healthy people without evidence of immunity 12 months or older.