Abstract: 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. 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.

Plain-language summary: The evidence in this review is up-to-date as of 25 February 2019. We included 35 randomised controlled trials (clinical studies where people are randomly put into one of two or more treatment groups) with 1474 participants, which tested several different corticosteroids, mostly delivered topically (on the skin). Corticosteroids were compared with one of the following: a placebo (a treatment that resembled the corticosteroid but had no active ingredient); a medicine from a category called calcineurin inhibitors; another medicine type; another corticosteroid or mode of delivery; the same corticosteroid plus an extra treatment; or an alternative treatment. Treatments were given for between one week and six months, with side effects measured throughout the treatment, and pain and healing measured at the end of treatment. Results from two studies showed that topical corticosteroids (e.g. clobetasol propionate, flucinonide, betamethasone and triamcinolone acetonide), when applied to the mouth in a sticky cream, may be effective in reducing and stopping pain. We do not have the evidence that topical corticosteroids can eliminate the oral lichen planus lesions, and we are uncertain about side effects. We found no consistent evidence that any particular corticosteroid was better than any other. Three studies using another topical medicine called tacrolimus (a calcineurin inhibitor) found that this medicine may be more effective than corticosteroids, but may be more likely to cause mild side effects. Available evidence comparing corticosteroids with other treatments is very limited. The reliability of most of the evidence is very low, so we cannot be sure about the findings and future research may lead us to different conclusions. The available evidence suggests that topical corticosteroids may be effective for treating painful oral lichen planus, but our confidence in these findings is limited as there were only a small number of studies and participants. There is some evidence that tacrolimus may be more effective than a corticosteroid, but evidence on negative side effects is inconclusive.