Varicella

Management Strategy

All healthy individuals, especially children, without a definite history of varicella should be vaccinated. In the United States, a live attenuated monovalent vaccine (VARIVAX) and a quadrivalent measles-mumps-rubella-varicella (MMRV) vaccine (ProQuad) are available, with the first dose administered at age 12 through 15 months and the second at age 4 through 6 years. For individuals who have only received a single dose of the vaccine, a second dose catch-up vaccination is recommended. Postexposure immunization may be effective for household contacts if given within 3 days of exposure, but should not be given to children with severe immune deficiency.

In healthy children younger than 12 years, symptomatic treatment is recommended. Acetaminophen (Tylenol) may be used in children with fever and pain, but aspirin should be avoided given the risk of Reye syndrome. Supportive topical treatment s for pruritus include oatmeal baths and calamine lotion . Topical or oral antibiotics are appropriate for children with a secondary bacterial infection. Oral aciclovir and valaciclovir are US Food and Drug Administration (FDA) approved for children ages 2 through 17 years with varicella, but antiviral therapy is generally not recommended in otherwise healthy children.

In healthy adolescents and adults , it is recommended that oral aciclovir , valaciclovir , or famciclovir be initiated within 24 hours of onset of the rash as antiviral therapy can decrease disease severity and duration. These patients should also be treated symptomatically. Smokers and patients with chronic lung disease have greater risk of complications, particularly varicella pneumonia, which has a mortality of 10–30%.

Pregnant women with varicella have an increased risk of complications. Infections during the first 20 weeks of pregnancy may result in congenital varicella syndrome, which includes limb hypoplasia and developmental abnormalities of the eyes and central nervous system. This syndrome occurs in 2% of pregnancies complicated by varicella during the first 20 weeks of gestation. Varicella zoster immune globulin (VZIG) is recommended for non-immune pregnant women within 96 hours of exposure to varicella. VZIG offers protection for 3 weeks and decreases the risk of fetal transmission. If VZIG is unavailable, affected women should receive intravenous immunoglobulin (IVIG) . Oral aciclovir , valaciclovir, or famciclovir should be initiated in pregnant women with varicella, especially in the second and third trimesters. Intravenous aciclovir is recommended in pregnant patients with serious complications of varicella, such as varicella pneumonia. Aciclovir, valaciclovir, and famciclovir are category B drugs in pregnancy, without significant risk of teratogenesis during pregnancy.

Neonates whose mothers develop varicella just before delivery (up to 5 days) or within 2 days after delivery should receive VZIG or IVIG prophylactically coupled with IV aciclovir .

Immunocompromised individuals exposed to varicella should receive VZIG or IVIG within 10 days of exposure. If the disease occurs despite administration of VZIG or IVIG, intravenous aciclovir should be given . Patients receiving high-dose corticosteroids (≥2 mg/kg/day or ≥20 mg/day prednisone or its equivalent) for more than 14 days are at risk of visceral involvement and death. Valaciclovir and famciclovir are often better alternatives given bioavailability and steadier plasma concentration. Resistance to aciclovir in immunocompromised individuals is rare. Patients requiring immunosuppressive therapy or solid organ transplantation should be screened for varicella zoster immunity and vaccinated at least 2 weeks prior to starting immunosuppressive treatment. Vaccination during immunosuppression is a complex decision requiring knowledge of a patient’s relative immune competence.

VZV can be identified by polymerase chain reaction (PCR) and DFA of skin scrapings from the base of a fresh vesicle. PCR is the preferred method given its rapidity and sensitivity. Viral culture has a poor yield and is not recommended. Tzanck smear is about 85% sensitive; it cannot differentiate between VZV and other herpesviruses.