A randomized clinical trial on the treatment of oral herpes with topical zinc oxide/glycine.

Context: A zinc preparation that provides a higher concentration of solubilized zinc in a minimally irritating formulation allowing controlled absorption would be of great clinical value for treating oral herpes.
Objective: To determine the effect of zinc oxide/glycine cream as a treatment for facial and circumoral herpes infection by measuring duration and intensity of signs and symptoms and assessing adverse effects.
Design: Double-blind, placebo-controlled, randomized clinical trial.
Setting: Subjects were enrolled from the general community through advertisements.
Patients: Forty-six subjects with facial or circumoral herpes infections.
Intervention: Application of a zinc oxide/glycine cream or a placebo cream every 2 hours until cold sore resolved or 21 days elapsed.
Main Outcome Measures: Duration of cold sore lesions, severity of signs and symptoms, and frequency of adverse effects.
Results: Subjects who began treatment with a zinc oxide/glycine cream within 24 hours of onset of signs and symptoms experienced a significantly shorter duration of cold sore lesions (mean, 5.0 days) than did subjects treated with a placebo cream (mean, 6.5 days). Subjects treated with the zinc oxide/glycine cream also experienced reduction in overall severity of signs and symptoms, particularly blistering, soreness, itching, and tingling. Side effects among subjects treated with zinc oxide/glycine cream were those expected from an ionic zinc salt solution. All were completely reversible and of short duration.
Conclusion: Zinc oxide/glycine cream is an effective treatment for facial and circumoral herpes infection with predictable adverse effects that are completely reversible.