Primary herpetic gingivostomatitis is a frequent problem in pediatrics. Complications of this are dehydration, pain and hospitalisation. The objective of this randomized controlled trial is to assess the clinical efficacy of oral Valacyclovir to decrease the duration of symptoms associated with acute herpes gingivostomatitis in children. This study will involve 80 children aged 1 to 8 years old to receive weight adjusted doses of valacyclovir for 7 days. The primary outcome measure will be the duration (in days) of feeding and/or drinking difficulties.

Inclusion criteria are :

• Children from 10 to 28 Kg of weight. The inclusion of participants is based on weight for practical/feasibility reasons because the study medication will be provided in tablet format. The lower limit of 10 kg is to limit to three strata of weight and limit costs engendered by the preparation of medication.

• Clinical diagnosis of herpetic gingivostomatitis according to the treating physician. This is described by the presence of:

  • Fever (>38.5° rectal, >38° oral) AND
  • Vesicular or ulcerative lesions located in the anterior of the mouth
  • Associated or not with perioral vesicular lesions Visiting the emergency department within the first 96 hours of the disease begin.

Exclusion criteria are :

• Duration of fever > 4 days
• Hospitalised patients
• Immunocompromised patients
• Patients with known hypersensitivity to Valacyclovir
• Patients with renal failure
• Children with complete incapacity of oral treatment intake
• Unable to be contacted for phone follow-up