Parenteral aciclovir for suspected herpes simplex virus infection in children: 0-18 years.

Background: Variations in neonatal aciclovir prescribing for suspected herpes simplex virus (HSV) disease are well-known, but there are limited data describing aciclovir prescribing in older children.

Methods: Medical records of neonates (≤28 days) and children (29 days to 18 years) prescribed intravenous aciclovir for suspected HSV disease (1 January 2019-12 December 2019) in eight Australian and New Zealand hospitals were reviewed. Prescribing indication, HSV testing, aciclovir prescription details, adverse events and discharge diagnosis were recorded.

Results: 1426 received empirical aciclovir. For neonates (n = 425), the median duration was 1 day (IQR 1-3), 411/425 underwent HSV investigations and 13/425 had HSV disease (two with disseminated encephalitis, four with encephalitis and seven with skin, eye, mouth disease). Of the 1001 children, 906 were immunocompetent. 136/906 suspected of mucocutaneous disease received aciclovir for a median of 2 days (1-2), 121/136 underwent HSV testing, and 69/136 had proven disease. 770/906 received aciclovir for suspected disseminated disease or encephalitis for a median of 1 day (1-2), 556/770 underwent HSV testing, and 5/770 had disseminated disease or encephalitis. Among 95 immunocompromised children, 53/58 with suspected mucocutaneous disease had HSV testing and this was confirmed in 22. Disseminated disease or encephalitis was suspected in 37/95, HSV testing conducted in 23/37 and detected in one. The median aciclovir duration was 3 (2-7) days for immunocompromised children. Nephrotoxicity occurred in 7/1426 and 24/1426 had an extravasation injury.

Conclusion: Frequent and often unnecessary intravenous aciclovir prescribing for suspected HSV encephalitis or disseminated disease occurred in children, as evidenced by incomplete HSV investigations and only 5/770 older children having the diagnosis confirmed.