Aciclovir
Aciclovir is an antiviral that blocks herpes simplex replication. NICE says children with suspected Eczema Herpeticum should start systemic (oral or IV) aciclovir immediately and be referred for same-day specialist advice (NICE QS44). In 1,331 hospitalised children, each day of delay in starting aciclovir lengthened hospital stay, by 98% if started on days 4–7 (Aronson, Pediatrics 2011). DermNet treats for 10–14 days or until the lesions heal, switching to IV if the child is unwell. It acts only on actively replicating Herpes Simplex Virus. It does not clear the latent virus, so later cold sores remain possible (DermNet HSV).
Aciclovir [treats] Eczema Herpeticum Aciclovir [opposes] Herpes Simplex Virus NICE CG57 [regulates] Aciclovir
Oral versus IV in children. NICE QS44 says “oral or intravenous aciclovir can be given depending on the clinical situation”, likely orally in primary care and intravenously in hospital. The underlying guideline (NICE CG57) advises starting oral aciclovir for a child with atopic eczema even when a suspected herpes lesion is localised. DermNet’s regimen is oral aciclovir 400–800 mg five times daily, or valaciclovir 1 g twice daily (adult doses; children are dosed by weight), for 10–14 days or until the lesions heal. IV is used if the patient is too sick to swallow or deteriorates despite treatment. There are no randomised trials comparing oral and IV routes. The only RCT of aciclovir in eczema herpeticum enrolled 60 adults on oral treatment versus placebo (Niimura 1988, cited by Aronson 2011). In Aronson’s cohort, delay was not linked to route (P = 0.85). Following DermNet, a toddler too unwell to take oral medicine, or one who keeps getting worse on oral treatment, moves to IV aciclovir; eye involvement needs same-day ophthalmology (NICE QS44).
Aciclovir [relates] NICE CG57 Eczema Herpeticum [precedes] Aciclovir
Conflict: [NICE CKS, n.d.] says immediate hospital admission should be arranged if eczema herpeticum is suspected (implying IV-capable care). [NICE QS44, 2013/2023] allows oral aciclovir in primary care plus same-day specialist advice. [DermNet, 2023] says prompt oral treatment “should eliminate the need for hospital admission”. Unresolved — already logged in eczema-infection-conflicts; cross-referenced in infection-treatment-conflicts.
Why prompt treatment matters. QS44 calls eczema herpeticum under-recognised and fast-deteriorating, with a risk of blindness or death. Aronson et al. studied 1,331 children (2 months–17 years) admitted to 42 US children’s hospitals. There were no deaths and 3.8% needed intensive care. Compared with day-1 starts, length of stay rose 11% when aciclovir started on day 2, 41% on day 3 and 98% on days 4–7. Topical steroids on admission did not lengthen stay, so parents need not stop Topical Corticosteroids while aciclovir is given (DermNet 2023). About 30% of the children also had Staphylococcus aureus infection, so Flucloxacillin is sometimes given alongside.
Topical Corticosteroids [relates] Aciclovir Staphylococcus aureus [worsens] Eczema Herpeticum
Safety in toddlers. Oral aciclovir is generally well tolerated. With IV aciclovir, the drug can crystallise in the kidneys, which is prevented by keeping the child well hydrated (Medscape 2002, search result only) (unverified). Topical aciclovir cream is for ordinary cold sores in older children and adults. It is not adequate for eczema herpeticum, which needs systemic treatment (NICE QS44). Patients with recurrent eczema herpeticum may be offered antiviral prophylaxis (Medscape 2002, search result only) (unverified).
Aciclovir [prevents] Eczema Herpeticum
What parents report (evidence: anecdotal). None of the 12 parent threads read for Parent Experiences (round 10) mentioned eczema herpeticum or aciclovir. Parents’ infection stories were about bacterial infection (“3 skin infections later and 3 lots of antibiotics”, r/ScienceBasedParenting) and hospital admissions for infected skin. The absence suggests parents rarely know about herpes-related emergencies, not that these never happen.
Aciclovir [relates] Parent Experiences
Connections
- Eczema Herpeticum — first-line treatment, source: NICE QS44; Aronson 2011
- Infected Eczema — treatment for viral infection, source: NICE QS44
- Herpes Simplex Virus — antiviral target, source: DermNet
- NICE CG57 — oral aciclovir even for localised suspected HSV lesions, source: NICE QS44
- Topical Corticosteroids — can be continued during aciclovir treatment, source: Aronson 2011; DermNet 2023
- Staphylococcus aureus — frequent co-infection needing antibiotics, source: Aronson 2011
- Flucloxacillin — sometimes given alongside for bacterial co-infection, source: Aronson 2011
- Parent Experiences — parent reports (anecdotal), source: round-10 forum threads