PEARLS 120, October 2008, written by Brian R McAvoy

Clinical question
How effective is acyclovir for treating primary herpetic gingivostomatitis (PHG)?

Bottom line
One trial (n=72) provided some limited evidence to suggest for children under 6 years of age with PHG acyclovir is effective in reducing the number of oral lesions (NNT* 2), preventing the development of new extraoral lesions (NNT 3), decreasing the difficulty experienced in eating (NNT 3) and drinking (NNT 5) and reducing admissions to hospital (NNT 12). * NNT = number needed to treat to benefit 1 individual.

Caveat
Only 2 trials, one with 72 participants and the other with 20 participants, were included in this review. The second study failed to report several methodological items and was inconsistent in its reporting of the outcomes measured.

Context
PHG is a highly contagious infection of the oral cavity which is caused by the herpes simplex virus. Only about 5-10% of patients initially infected with the virus develop clinical lesions. It is prevalent in children and adolescents and sometimes can cause uncomfortable symptoms including eating and drinking difficulties and, rarely, life threatening encephalitis.

Cochrane Systematic Review
Nasser M et al. Acyclovir for treating primary herpetic gingivostomatitis. Cochrane Reviews 2008, Issue 4. Article No. CD006700. DOI: 10.1002/14651858.CD006700.pub2. This review contains 2 trials involving 92 participants.