Antiviral treatment of herpes simplex infection in neonates and pregnant women.

Herpes simplex infections in neonates include (1) infections beginning in skin or mucous membranes, (2) infections of the central nervous system, and (3) disseminated herpes of the newborn. Early recognition of infections beginning in skin or mucous membranes is essential because 75% will disseminate internally if untreated. Skin lesions provide important diagnostic clues in herpes of the nervous system and disseminated herpes, but they often appear late and in only about 60% of infected neonates. Acyclovir and vidarabine are effective therapies but they must be administered early to prevent serious damage or death. Herpetic skin lesions in neonates may be confused with pyodermas. Direct immunofluorescence and cultures are reliable diagnostic tests. Congenital herpes may cause widespread skin involvement and multiple eye and nervous system diseases. The mother is the source of neonatal herpes in about two thirds of cases. Asymptomatic genital shedding of virus late in pregnancy does not accurately predict whether maternal cultures will be positive at the time of delivery. The risk of the infant acquiring neonatal herpes from a mother with recurrent herpes at birth is about 5%, but the risk is much higher if the mother has true primary genital infection.