Introduction

Herpes Simplex Virus Type 1 (HSV-1) is one of the most widespread infections that can affect the orofacial region. Acyclovir is a standard topical therapy but is less effective than oral or intravenous treatment. Oral and intravenous acyclovir is only prescribed for patients with frequent recurrences/severe pain leading to widespread use and increased resistance. Photodynamic therapy (PDT) uses a photosensitizer and light to inactivate viruses and may be an alternative treatment.

Aim

To compare photodynamic therapy (PDT), Topical Acyclovir (AC), and the association of both in the healing process and self-reported symptomologies of HSV-1 recurrences

Patient Profile

Immunocompetent adult patients presenting an HSV-1 lesion during the vesicle phase

Methods

• N=75 enrolled in a randomized clinical trial

Treatment

Three different treatments were applied:

• Group 1 (n=25) - PDT using methylene blue as a photosensitizer and 660 nm wavelength laser as a light source
• Group 2 (n=16) - Topical therapy with antiviral Acyclovir at 5% (AC)
• Group 3 (n=18) - Association of both treatments (PDT + AC)

Study endpoints

7- days follow-up to assess outcomes

• Primary: Wound size reduction
• Secondary: Healing time, pain, tingling, edema

Results

For both primary and secondary outcomes, statistical difference was noted amongst groups only on day 1.

1. Wound size reduction: On day 1, AC group showed less reduction of the lesion when compared to the AC-PDT group (p = 0.0131). From day 2, there were no significant differences in lesion sizes (p > 0.05) between the 3 treatments
2. Healing time: No statistically significant difference was found among the three treatments
3. Edema: On day 1, AC group showed statistically higher edema when compared to PDT and PDT + AC (p = 0.0182), while PDT and PDT + AC were similar
4. Pain reduction: No significant difference observed between treatments at any of the observed times
5. Tingling: On day 1, significant reduction was observed in PDT group in tingling scale (p =0.0048) compared to AC group. There was no difference in all groups up to 7 days

Safety

No side-effects noted for PDT treatment

Conclusion

Only on day 1, photodynamic therapy showed positive effects in treatment of herpes lesions in comparison to topical acyclovir.

Reference

Photodiagnosis Photodyn Ther. 2021 Mar:33:102093