Background: Research results on the efficacy of sunblock sticks in avoiding or reducing Herpes labialis (HL) recurrences are contradictory and has shown mixed results, with some protection reported under experimental conditions that could not be replicated under natural conditions.
Objective: The purpose of the present work was to carry out an in vivo test on the effectiveness of a protective lip product in preventing recurrent HL in natural conditions during summer.
Methods: An exploratory randomized crossover study was performed on 20 adult volunteers who served as their own controls during the analysis. The study was conducted between May and July 2017 around the summer solstice. During the two-month period, volunteers had to perform normal daily activities and also needed to go to the beach in Sardinia; thirty subjects applying SPF 30 protection and 30 without protection.
Results: In individuals with stick protection, the number of HL attacks was significantly reduced. Based on association between different parameters, which emerged from the medical history and the post-test questionnaire, it was found that male individuals over 44 y of age and with Fitzpatrick skin type 2 were the most exposed to recurrence.
Conclusion: HL recurrence rate can be reduced by using sunblock stick in summer.
Keywords: Herpes labialis; UV exposure; sunblock.