BACKGROUND AND OBJECTIVE: Recurrent herpes labialis is a common infection of the mouth area, caused by herpes simplex virus. This infection appears in the mucus or lip skin and is commonly known as oral herpes. The purpose of this study was to compare the effectiveness of Mellisan gel and acyclovir 5% cream in the improvement of recurrent herpes labialis.

METHODS: This double-blind clinical trial was conducted on 60 patients (14 men and 46 women), with the average age of 23.8 years (minimum of 20 and maximum of 32 years) and a prior history of recurrent herpes labialis three times a year. The previously-coded medicines were randomly distributed among patients. The subjects were asked to apply the cream or gel locally on the infected region three times a day, according to the manufacturer's instructions. All patients were examined within one, two, four and seven days after using the cream or gel to determine the changes in pain intensity, size of the ulcer, inflammation and recovery time. IRCT: 13870819144281. 

FINDINGS: Mellisan gel and acyclovir cream were not significantly different in reducing the size of the ulcer, inflammation or the associated side-effects. Mellisan gel was accompanied by a significant reduction in pain intensity in patients on the second and fourth days of the examination (p=0.0001 and p=0.02, respectively). Moreover, on the second day, there was a significant difference in recovery (p=0.001).

CONCLUSION: The results of this study suggested that Mellisan gel is more effective than acyclovir cream in terms of pain reduction and recovery, whereas no significant difference was observed regarding the size of the ulcer or inflammation. Also, the administration of Mellisan gel and acyclovir cream was associated with no side-effects.