Background Varicella infection is very common in children and easily transmitted. In immunocompetent, varicella infection is usually mild and self-limiting. However, in immunocompromised, varicella infection has the potential to disseminate and cause complications, one of which is pneumonia, due to impaired cellular immunity that the morbidity and mortality is much higher. Acyclovir is an antivirus that is effective for varicella in immunocompetent children.

Objectives Evaluate evidence exists to date regarding the efficacy and safety of acyclovir in reducing morbidity (disease severity, duration of illness and dissemination) and mortality of immunocompromised children with varicella.

Methods Literature searching was conducted on PubMed, Cochrane and MEDLINE with the keywords of ‘acyclovir’, ‘varicella’, ‘immunocompromised’ and ‘children’. After filtering articles based on inclusion and exclusion criteria without time limitation, we found 3 relevant articles. One was excluded since it didn’t apply blinding and thus result to the final 2 randomized clinical trials that were critically appraised based on the validity, importance and applicability criteria of Oxford Center for Evidence-Based Medicine (2011).

Results In terms of efficacy, 12 (48%) out of 25 placebo recipients were withdrawn from the double-blind randomized treatment to be treated by open intravenous acyclovir due to their worsening condition, only 1 out of 25 (4%) who were treated by intravenous acyclovir and only 2 out of 25 (8%) who were treated by oral acyclovir were similarly withdrawn (p<0.001). Consequently, intravenous and oral acyclovir both significantly reduce varicella dissemination and mortality. The use of intravenous acyclovir also significantly accelerates crusts formation (p<0.001), reduces the duration of varicella infection. In terms of safety, there were increase in blood urea nitrogen levels without any clinical manifestation and acute diarrhea without dehydration which was mild and self-limiting.

Conclusions All immunocompromised children who develop varicella should be considered for early treatment with either intravenous or oral acyclovir since both are safe and significantly prevent worsening condition of the patient due to varicella dissemination. Intravenous acyclovir also reduces the duration of infection. All patients need to be monitored closely by the physician, especially the one who receives oral therapy, that any whose condition does not show improvement should be considered for intravenous route.