We read the article ''Treatment of oral lichen planus with the 308-nm UVB excimer laser-early preliminary results in eight patients '' by Köllner et al. [1] with great interest. We, too, evaluated the 308 nm excimer laser in a pilot study on four patients presenting erosive oral lichen planus (EOLP).
PATIENTS AND METHODSFour patients, with at least two lesions EOLP confirmed by biopsy, were included in an open prospective study. No previous treatment had provided satisfactory results on any of the patients. Each patient was treated with the 308 nm excimer laser (TALOS 1 , WaveLight Laser Technologie AG, Erlangen, Germany), twice a week for 12 sessions. Initial fluences were 50 mJ/cm 2 . Then fluences were increased by 50 mJ/cm 2 every two sessions up to 200 mJ/ cm 2 . Local or systemic treatments, potentially effective for EOLP, were stopped 1 month before the onset of sessions and were forbidden throughout the study. Effectiveness was evaluated at the end of the sessions, and then 1 month after the end of the treatment, on a clinical scoring basis already used in a previous study, taking into account the spreading of the lesions and the pain between and during meals [2]. Side effects were noted at each session. Tolerance was evaluated by the patients, with a visual analogical scale (0 ¼ poor; 10 ¼ excellent).
RESULTSThree women and one man, 40-85-year-old, were included. A clear improvement was observed in only one of them. The onset of improvement was noted at the third session with a cumulated dose of 0.2 J/cm 2 . The initial clinical score was 9/12 and decreased to 3/12 after the 12 sessions (cumulated dose: 1.6 J/cm 2 ). This score remained stable (3/12) without any additional treatment, 1 month after the end of the sessions. On the other hand, no improvement was observed in the other three patients. In two of them, the laser allowed only a stabilization of the lesions. In the last patient, a worsening of the disease was noted (score from 6/12 to 9/12). Side effects were limited to a moderate erythema. Tolerance was evaluated by the patients on average at 9.6/10.
DISCUSSIONThe results obtained in this study are disappointing, as only one of our four patients had a clear improvement of his lesions and no complete healing could be achieved. However, the photobiological effect of the 308 nm UVB on lymphocytes supports the view that this laser could be theoretically effective in the treatment of EOLP [3]. The difference of effectiveness, compared with the results of Köllner et al.[1], could be explained by several factors. First, we did not use a special handpiece. However, the 5 mm diameter handpiece that was used in this study, allowed us to treat the intra-oral lesions quite easily and does not appear to be responsible for the difference in results between the two studies. More probable is the fact that the rate of session could be an important factor. Degree of exposure to irradiation and duration of treatment do not explain this difference, as they were quite similar in the two studies. Additional studies ...
