Oral acyclovir therapy initiated within 24 hours of illness for otherwise healthy children with varicella typically will result in a 1-day reduction of fever and approximately a 15% to 30% reduction in the severity of cutaneous and systemic signs and symptoms. Therapy has not been shown to reduce the rate of acute complications, pruritus, spread of infection,or duration of absence from school. Its long-term effect on the rate of occurrence of zoster is unknown. To date, no significant adverse effects of oral acyclovir therapy in otherwise healthy children have been demonstrated. In adults, delay of therapy beyond the first 24 hours of illness results in loss of therapeutic effect. The cost-benefit ratio of therapy is currently unknown, and its determination is extremely complex.
Recommendations: 1. Oral acyclovir therapy is not recommended routinely for the treatment of uncomplicated varicella in otherwise healthy children. This recommendation is based on the marginal therapeutic effect, the cost of the drug, feasibility of drug delivery in the first 24 hours of illness. Such a decision should be based on an informed discussion among the physician, parent, and patient. 2. For certain groups at increased risk of severe varicella or its complications, oral acyclovir therapy for varicella, if it can be initiated within the first 24 hours after the onset of rash, should be considered. These groups include the following: a. Otherwise healthy, nonpregnant individuals 13 years of age or older. b. Children older than 12 months with a chronic cutaneous or pulmonary disorder and those receiving long-term salicylate therapy, although in the latter instance a reduced risk for Reye syndrome has not been shown to result from oral acyclovir therapy nor from milder illness with varicella.(ABSTRACT TRUNCATED AT 250 WORDS)