Background: Cutaneous lichen planus (CLP) is an inflammatory dermatosis. Its chronic relapsing course and frequently spontaneous regression hamper the assessment of treatment effectiveness.
Objective: To evaluate the efficacy of available treatment modalities for CLP.
Data sources: PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov registry.
Methods: We performed a systematic review of the current literature. All randomized controlled trials, nonrandomized case-control studies, and cohort studies with more than one treatment arm were included. The primary outcomes were complete response and time to complete response. The secondary outcomes were partial response, relapse, time to relapse, reduction of itch, the adverse event rate, and withdrawal due to adverse events.
Data synthesis: Sixteen studies met the inclusion criteria, of which 11 were randomized controlled trials. Most trials had a small sample size. In the rare studies in which variants other than generalized or classic lichen planus were included, they could not be analyzed separately. Body-of-evidence quality ranged from very low to moderate. Acitretin, sulfasalazine, and griseofulvin were associated with increased overall response rates in comparison with placebo. Narrow-band ultraviolet B radiation (NBUVB) was more effective than 6 weeks' low-dose prednisolone in achieving a complete response, and prednisolone was more effective than enoxaparin. Hydroxychloroquine was more effective than griseofulvin in achieving an overall response. Betamethasone valerate 0.1% ointment had comparable efficacy to calcipotriol ointment. Methotrexate was effective, with a nonsignificant difference in the complete response rate in comparison with oral betamethasone. In nonrandomized controlled trials, oral psoralen plus ultraviolet A photochemotherapy (PUVA) had comparable efficacy to a PUVA bath and NBUVB. Psoralen plus sunlight exposure (PUVASOL) and betamethasone dipropionate 0.05% cream were effective relative to a short course of oral metronidazole.
Conclusions: Several effective treatment options are available for CLP. Further well-designed studies are warranted to investigate the efficacy of topical glucocorticoids-the current first-line therapy-as well as other treatment modalities, and the treatment of different variants of CLP.