HSV keratitis in children

Herpes simplex virus (HSV) keratitis occurs less often in children than in adults, but the infection tends to be more severe in children and mandates aggressive treatment to reduce the risk for corneal opacity and irregular astigmatism leading to amblyopia and poor quality of vision, said Marc Labetoulle MD, PhD, at the 2017 WSPOS Paediatric Subspecialty Day meeting in Lisbon, Portugal. “Topical or systemic antiviral agents can be prescribed as curative treatment for HSV epithelial keratitis, but intravenous acyclovir is indicated in cases of necrotising stromal keratitis. Corticosteroids should not be given for either of those conditions, but a topical corticosteroid combined with oral acyclovir or valacylovir is recommended for treatment of non-necrotising stromal keratitis,” said Dr Labetoulle, Head, Department of Ophthalmology, Bicêtre Hospital, Le Kremlin-Bicêtre, France. Discussing topical antiviral treatment for HSV keratitis in children, Dr Labetoulle said that only trifluridine and acyclovir are authorised for paediatric use, at least in France. Topical ganciclovir is a reasonable choice, however, considering that at the dose given, potential systemic exposure is >500-fold lower than would occur with systemic ganciclovir treatment in children with cytomegalovirus retinitis. Regarding systemic antiviral treatment for HSV keratitis, there are no published data on use of acyclovir in children aged younger than two years, but it is commonly used in the paediatric age group for other indications, even at a high dose. Administration in children is facilitated with acyclovir syrup 200mg/5mL and acyclovir suspension 800mg/10 mL. Dr Labetoulle cautioned that sorbitol and glycerol contained in the suspension can cause diarrhoea, particularly in children aged younger than six years. There are no published data on use of oral valacylovir in children younger than 12 years of age or for oral famciclovir in patients younger than 18 years of age. “However, because valacylovir is converted to acyclovir after ingestion, there is no scientific reason that it should be contraindicated in kids, providing that renal function is monitored”, Dr Labetoulle said. The dosage for oral antiviral medications to treat HSV keratitis in children is controversial. Some authors recommend using the same dosage as in adults, whereas others recommend using half the adult dosage in children whose body weight is below 20 kg. Dr Labetoulle noted that the frequency of HSV keratitis recurrence is about two-fold higher in children than in adults. While no children were enrolled in the Herpetic Eye Disease Study that established the efficacy of oral acyclovir for reducing HSV keratitis recurrence, Dr Labetoulle suggested that for suppressive treatment in children, acyclovir could be given at half the recommended adult dosage. “Collaboration with a paediatrician is mandatory, however, when treating very young children,” he stressed. Marc Labetoulle: marc.labetoulle@aphp.fr