Interventions for treating oral lichen planus.

BACKGROUND: Oral lichen planus is a chronic autoimmune disease of unknown aetiology that affects the inner surface of the mouth. The symptomatic forms are painful,tend to worsen with age and with remissions being rare. Current treatment is palliative and not curative, many topical and systemic agents have been tried with little hard evidence for efficacy.

OBJECTIVES: To assess the effectiveness and safety of any form of palliative therapy against placebo for the treatment of symptomatic oral lichen planus.

SEARCH STRATEGY: Electronic databases, handsearching of conference proceedings and specific journals, researchers in the field, drug manufacturers.

SELECTION CRITERIA: Any placebo-controlled trial of palliative therapy for symptomatic oral lichen planus, using a randomised or quasi-randomised design that measured changes in symptoms and/or clinical signs.

DATA COLLECTION AND ANALYSIS: Change in symptoms (pain, discomfort) and clinical signs (visual impression, lesion measurements) at the end of therapy. Odds ratio of improvement vs no improvement for each trial outcome and pooling where appropriate.

MAIN RESULTS: A total of nine RCTs were identified. The nine interventions were grouped into four separate classes (cyclosporines, retinoids, steroids and phototherapy) for comparison. No therapy was replicated exactly, the closest replication involved two trials using high and low dose cyclosporine mouthwash. Only trials recording the same outcomes in each therapeutic class were pooled. The largest number of pooled trials was three. Large odds ratios with very wide confidence intervals indicating a statistically significant treatment benefit were seen in all trials. However this has to be tempered by considerations of the small study sizes, the lack of replication, the difficulty in measuring outcome changes and the very high likelihood of publication bias. Only systemic agents were associated with treatment toxicities, all other side-effects were mild and mainly limited to local mucosal reactions.

REVIEWER'S CONCLUSIONS: The review provides only weak evidence for the superiority of the assessed interventions over placebo for palliation of symptomatic OLP. The results highlight the need for larger placebo-controlled RCTs with more carefully selected and standardised outcome measures before between-treatment comparisons can be properly interpreted.