Supplementary Material for: A SYSTEMATIC REVIEW AND BAYESIAN NETWORK META-ANALYSIS OF MEDICAL THERAPIES FOR LICHEN PLANOPILARIS.

BACKGROUND: Lichen planopilaris (LPP) is a primary chronic lymphocytic cutaneous disorder that selectively destroys the hair follicles, resulting in a scarring alopecia. Unfortunately, current available treatments are not fully effective to stop hair loss, and the level of evidence for medical interventions is weak. METHODS: A systematic review and meta-analysis was performed including randomized trials that report the outcomes of lichen planopilaris activity index (LPPAI). These articles were pooled and a network meta-analysis (NAM) was conducted. RESULTS: A total of seven studies was identified and included in meta-analysis, comprising 251 LPP patients. The NMA showed the mean difference in LLPAI was significantly superior with the combination of clobetasol plus N-acetylcysteine (mean difference: -2.0, 95%CI=-3.43- -0.51) and the combination of clobetasol plus pentoxyfilline (mean difference: -1.62, 95%CI=-3.0- -0.25) compared to the treatment of reference (clobetasol). The NMA showed cyclosporine (mean difference: 2.05 95%CI= 0.68-3.49), methotrexate (mean difference: 1.95 95%CI= 1.23-3.17), the combination of methotrexate plus prednisolone (mean difference: 1.56 95%CI= 0.25-2.96) were significantly worse than hydroxychloroquine according to the differences in LLPAI. CONCLUSION: This work is the first NMA in LPP and hence, it can be helpful serving as an initial step towards better evidence-based decisions in the treatment of this challenging condition. We propose a triple combined approach consisting of topical clobetasol, hydroxychloroquine and N-acetylcysteine as resulted in the most effective approach. Considering the poor outcomes observed with pioglitazone, mycophenolate mofetil, and cyclosporine, it is advisable to contemplate the use of these medications in patients who have not responded adequately to more efficacious alternatives.