Effect of combined antimicrobial photodynamic therapy and photobiomodulation therapy in the management of recurrent herpes labialis: a randomized controlled trial

This study aimed to study the effect of combined antimicrobial photodynamic therapy (aPDT) and photobiomodulation therapy (PBMT) in the management of recurrent herpes labialis (RHL). Sixty participants were randomly assigned into three groups. Group 1 (control): 5% Acyclovir was applied as a topical cream, and a non-activating laser was applied. Group 2 (PBMT): PBMT was applied using a low-level laser therapy (LLLT) and a placebo cream. Group 3 (aPDT + PBMT): aPDT using 0.1% methylene blue with PBMT and a placebo cream. A laser diode emitting light at a wavelength of 650 nm and a power output of 100 mW was applied to each spot for 120 s. The parameters of aPDT were a wavelength of 650 nm, with power and energy density parameters set at 100 mW/ 0.1 W and 24 J/cm², respectively. Pain intensity was measured using a visual analog scale (VAS). At the baseline (t₀). After applying the laser (t₁). After 48 h (t₂). After utilizing the laser in the second session (t₃). After 7 days (t₄). The point of healing was the spontaneous shedding of the crust. The aPDT + PBMT group outperforms the control group in reducing pain intensity at t₁ (p = 0.011), t₂ (p = 0.041), and t₃ (p = 0.005). In addition, the aPDT + PBMT group outperformed the PBMT group at t₃ (p = 0.020). aPDT + PBMT outperforms control (p = 0.001) and PBMT (p = 0.090) groups in healing. The findings indicate that aPDT and PBMT offer a promising approach to treating RHL.