Could photodynamic therapy be utilized as a treatment modality for oral lichen planus?

Oral lichen planus (OLP) is a chronic inflammatory disease. There is no standard treatment modality for OLP. Recently, photodynamic therapy (PDT) has been advocated as a new treatment modality for OLP.

The aim of the present study is to compare the effect of PDT using methylene blue (MB) as a photosensitizer to the effect of topical corticosteroids in the treatment of erosive OLP lesions.

Our study included 20 patients with erosive OLP. Patients were divided into two groups. The study group included 10 patents which received MB-PDT. Patients were instructed to use MB as mouth path for 5 min. After 10 min, we applied focal red light on OLP lesions (wavelength 660 nm, Intensity 100-130 m W/cm2) for 2 min. The PDT was applied twice a week for four weeks. In the control group, 10 patients were instructed to apply topical betamethasone valerate ointment 100 mg on OLP lesion three times per day for four weeks. Subjective, objective scores and lesion size were recorded at time zero, after 2 weeks and after 4 weeks from the start of treatments.

Both groups showed statistically significant differences between time zero and the 4^th week of treatment in subjective, objective scores and the area of the lesions. MB-PDT showed a higher degree of improvement than topical corticosteroids between time zero and the 4^th week of treatment.

Photodynamic therapy can be used as a treatment for erosive OLP. PDT offers improvement of OLP subjective and objective scores without major side effects.