Iontophoretic Application of Acyclovir Cream to Treat Recurrent Herpes Labialis

This is a multicenter, randomized, double-blind, placebo-controlled study to evaluate the safety and efficacy of iontophoretically-applied acyclovir 5% cream for the treatment of herpes simplex labialis lesions including an open label arm using Zovirax (acyclovir) Cream 5% as per standard of care in the same patient population. Subjects who meet the eligibility requirements at the screening/randomization visit will be randomized in a 1:1:1 ratio to one of the three treatment groups. After being enrolled and randomized into the study, subjects will be sent home with a locked kit containing the iontophoretic device with either active or placebo cream or a locked kit containing Zovirax Cream 5%. At first signs and/or symptoms of a recurrent herpetic episode (Stage 0 or 1, prodromal or erythema), the lesion will be confirmed by telephone interview with the subject, and upon confirmation of the lesion, the subject will be given the combination to the locked kit and instructed to begin treatment immediately, thereby initiating the Treatment Phase of the study. Subjects will be followed for at least 5 consecutive days post-treatment up until a maximum of 10 consecutive days post-treatment, until the herpes lesion is healed.