A systematic review of placebo-controlled randomized clinical trials of treatments used in oral lichen planus

Abstract

Background: Oral lichen planus (OLP) is one of the commoner conditions seen in oral medicine clinics. Current treatments are palliative rather than curative. Numerous treatments have been tried but many have not been evaluated in randomized controlled trials (RCTs).

Objectives: To review the effectiveness and safety of any therapy compared with placebo for the treatment of symptomatic OLP.

Methods: A systematic review of 11 RCTs, totalling 223 patients was done. The main outcome measures used were improvement of signs (erythema, reticulation, ulceration) and symptoms (pain, discomfort) usually after 8 weeks of therapy.

Results: Eleven interventions were grouped into four therapeutic classes (topical ciclosporins, topical or systemic retinoids, topical steroids and phototherapy) for comparison. No therapy was replicated exactly. Trials recording the same outcomes in each therapeutic class were pooled. The largest number of pooled trials was four. Small odds ratios with very wide confidence intervals indicating statistically significant but imprecisely known treatment benefits were seen in all but one trial. Only systemic agents were associated with treatment toxicities; all other side-effects were mild and mainly local.

Conclusions: The results are tempered by the small study sizes, lack of replication, lack of standardized outcome measures and the very high likelihood of publication bias. Therefore this review provides only circumstantial evidence for the superiority of the assessed interventions over placebo for the palliation of symptomatic OLP. There is a need for larger placebo-controlled RCTs with carefully selected and standardized outcome measures.