Background and objectives: Lichen planopilaris (LPP) is one of the important causes of cicatricial alopecia. We aimed to evaluate the efficacy and safety of low-dose naltrexone (LDN) in the setting of a clinical trial in patients with LPP.Methods: We included patients with LPP between 2018 and 2020. Patients were allocated to two groups. The first group received topical clobetasol plus oral low dose naltrexone (3 mg) while the second received topical clobetasol plus placebo. The assessment was made for the disease severity by lichen planopilaris activity index (LPPAI) instrument and the safety of the drug in 2-month intervals up to 6 months. To compare both groups, we used the ANOVA test for repeated measures. Clinical trials registry code: IRCT20180809040747N1.Results: Thirty-four patients were analyzed in an intention-to-treat fashion. There was a decrescendo pattern on LPPAI scores that was statistically significant within the LDN (p = .001) but almost significant within the placebo group (p = .060) and non-significant between the groups (p = .813). The side effects attributable to the low dose naltrexone was not statistically different between studied groups.Conclusion: Low-dose naltrexone (3 mg) failed to improve the severity of the LPP more than what is achievable with topical clobetasol.
Keywords: Lichen planopilaris; alopecia; clobetasol; naltrexone.