Low-Dose Oral Minoxidil in Lichen Planopilaris: Efficacy and Safety

Abstract

Background: Treating lichen planopilaris (LPP) is challenging for dermatologists. Along with anti-inflammatory agents, another goal of treatment is to improve hair thickness in unaffected areas to cover the scars. Aim: To evaluate the effectiveness and safety of adding low-dose oral minoxidil (OM) to the standard anti-inflammatory treatment of LPP. Method: A total of 37 patients with LPP were randomly assigned to receive either 15 mg/week methotrexate (MTX) plus topical clobetasol or 1 mg/day minoxidil in addition to MTX plus clobetasol for 6 months. The Lichen Planopilaris Activity Index (LPPAI), dermoscopy, and standard photography evaluated the treatment efficacy. Results: Both groups exhibited a significant improvement in LPPAI (p < 0.001). The following signs/symptoms demonstrated notable improvements in frequency and/or severity in both groups: pruritus, anagen pull test, follicular prominency, scalp erythema, perifollicular erythema, milky red area, and pigmentation. However, pain, burning sensation, hair tufting, and spreading only improved in the MTX + low-dose OM group. Elongated blood vessels did not improve in either group. In terms of hair thickness and density, there was no significant difference between the two groups. Conclusion: The addition of 1 mg/day minoxidil to the standard treatment of LPP was found to be safe but did not yield significant effects on LPPAI and hair density/thickness. Notably, two patients who received low-dose OM (2/19, 10.5) showed hair regrowth in scarring areas. Trials with higher doses of minoxidil may be promising.