Interventions for treating oral lichen planus: corticosteroid therapies.

BACKGROUND Oral lichen planus (OLP) is a relatively common chronic T cell-mediated disease, which can cause significant pain, particularly in its erosive or ulcerative forms. As pain is the indication for treatment of OLP, pain resolution is the primary outcome for this review. This review is an update of a version last published in 2011, but focuses on the evidence for corticosteroid treatment only. A second review considering non-corticosteroid treatments is in progress. OBJECTIVES To assess the effects and safety of corticosteroids, in any formulation, for treating people with symptoms of oral lichen planus. SEARCH METHODS Cochrane Oral Health's Information Specialist searched the following databases to 25 February 2019: Cochrane Oral Health's Trials Register, CENTRAL (2019, Issue 1), MEDLINE Ovid, and Embase Ovid. ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. There were no restrictions on language or date of publication. SELECTION CRITERIA We considered randomised controlled clinical trials (RCTs) of any local or systemic corticosteroid treatment compared with a placebo, a calcineurin inhibitor, another corticosteroid, any other local or systemic (or both) drug, or the same corticosteroid plus an adjunctive treatment. DATA COLLECTION AND ANALYSIS Three review authors independently scanned the titles and abstracts of all reports identified, and assessed risk of bias using the Cochrane tool and extracted data from included studies. For dichotomous outcomes, we expressed the estimates of effects of an intervention as risk ratios (RR), with 95% confidence intervals (CI). For continuous outcomes, we used mean differences (MD) and 95% CI. The statistical unit of analysis was the participant. We conducted meta-analyses only with studies of similar comparisons reporting the same outcome measures. We assessed the overall certainty of the evidence using GRADE. MAIN RESULTS We included 35 studies (1474 participants) in this review. We assessed seven studies at low risk of bias overall, 11 at unclear and the remaining 17 studies at high risk of bias. We present results for our main outcomes, pain and clinical resolution measured at the end of the treatment course (between one week and six months), and adverse effects. The limited evidence available for comparisons between different corticosteroids, and corticosteroids versus alternative or adjunctive treatments is presented in the full review. Corticosteroids versus placebo Three studies evaluated the effectiveness and safety of topical corticosteroids in an adhesive base compared to placebo. We were able to combine two studies in meta-analyses, one evaluating clobetasol propionate and the other flucinonide. We found low-certainty evidence that pain may be more likely to be resolved when using a topical corticosteroid rather than a placebo (RR 1.91, 95% CI 1.08 to 3.36; 2 studies, 72 participants; I² = 0%). The results for clinical effect of treatment and adverse effects were inconclusive (clinical resolution: RR 6.00, 95% CI 0.76 to 47.58; 2 studies, 72 participants; I² = 0%; very low-certainty evidence; adverse effects RR 1.48, 95% 0.48 to 4.56; 3 studies, 88 participants, I² = 0%, very low-certainty evidence). Corticosteroids versus calcineurin inhibitors Three studies compared topical clobetasol propionate versus topical tacrolimus. We found very low-certainty evidence regarding any difference between tacrolimus and clobetasol for the outcomes pain resolution (RR 0.45, 95% CI 0.24 to 0.88; 2 studies, 100 participants; I² = 80%), clinical resolution (RR 0.61, 95% CI 0.38 to 0.99; 2 studies, 52 participants; I² = 95%) and adverse effects (RR 0.05, 95% CI 0.00 to 0.83; 2 studies, 100 participants; very low-certainty evidence) . One study (39 participants) compared topical clobetasol and ciclosporin, and provided only very low-certainty evidence regarding the rate of clinical resolution with clobetasol (RR 3.16, 95% CI 1.00 to 9.93), pain resolution (RR 2.11, 95% CI 0.76 to 5.86) and adverse effects (RR 6.32, 95% CI 0.84 to 47.69). Two studies (60 participants) that compared triamcinolone and tacrolimus found uncertain evidence regarding the rate of clinical resolution (RR 0.86, 95% CI 0.55 to 1.35; very low-certainty evidence) and that there may be a lower rate of adverse effects in the triamcinolone group (RR 0.47, 95% CI 0.22 to 0.99; low-certainty evidence). These studies did not report on pain resolution. AUTHORS' CONCLUSIONS Corticosteroids have been first line for the treatment of OLP. This review found that these drugs, delivered topically as adhesive gels or similar preparations, may be more effective than placebo for reducing the pain of symptomatic OLP; however, with the small number of studies and participants, our confidence in the reliability of this finding is low. The results for clinical response were inconclusive, and we are uncertain about adverse effects. Very low-certainty evidence suggests that calcineurin inhibitors, specifically tacrolimus, may be more effective at resolving pain than corticosteroids, although there is some uncertainty about adverse effects and clinical response to tacrolimus showed conflicting results.