Efficacy of photobiomodulation therapy in recurrent herpes labialis management: a randomized controlled trial

Recurrent Herpes Labialis (RHL) is a viral disease caused by the reactivation of Herpes Simplex Virus type 1 (HSV-1), which remains latent in sensory nerve cells after the primary infection. According to the World Health Organization (WHO), approximately 3.7 billion individuals under the age of 50 are infected with Herpes Simplex Virus type 1, which represents 67% of the world's population.

Acyclovir, a guanosine analogue nucleoside, is the specific antiviral drug used to treat Herpes Simplex Virus infections. It has gained significant attention in recent years due to the development of new antiviral factors. While many of these factors have already been developed and employed in managing Herpes Simplex infections, the search for new sources of antiviral drugs remains a significant challenge for doctors and researchers in the field of microbiology. Thus, it has become crucial to explore new avenues for researching modern therapeutic factors that work through mechanisms different from nucleoside analogues.

In this context, a study titled “Efficacy of photobiomodulation therapy in recurrent herpes labialis management: a randomized controlled trial” was conducted at the Faculty of Dentistry, Damascus University, with the aim of evaluating the therapeutic effectiveness of Photobiomodulation Therapy (PBMT) in managing Recurrent Herpes Labialis (RHL) by assessing both pain and clinical recovery.

A randomized, double-blind, controlled trial was conducted on 40 patients with RHL, and they were randomly divided into two groups, where 20 patients received treatment with PBMT (650 nm, 100 mW, 4.7 J/cm2), continuous mode, for 120 s, and placebo cream, while another 20 patients (control group) were treated with acyclovir cream 5% (5 times/5 days) and passive laser. Pain was assessed at five different times. The day when the complete disappearance of the pain was observed and the day when the crust fell off spontaneously were also recorded.

The study results showed that the pain level in the control group was significantly higher than that in the PBMT group after the second application of the laser, while the differences were not significant between the two groups at other times. The pain in the PBMT group disappeared faster than that in the control group, but the difference was not significant in terms of clinical recovery.

The study concluded that photobiomodulation therapy of herpes labialis reduced pain significantly faster than acyclovir, but there was no difference in healing time between the groups in light of the parameters used in this study.