Safety and Efficacy of Minoxidil Treatment in Scarring Alopecia: A Scoping Review

March 2024 | Volume 23 | Issue 3 | 146 | Copyright © March 2024


Published online February 14, 2024

Nathalie Ly BSb,c, Erin M. McClure BSa,d, Maria K. Hordinsky MDb, Ronda S. Farah MDb, Song Y. Park MDa

aDivision of Dermatology, Department of Medicine, University of Washington, Seattle, WA
bDepartment of Dermatology, University of Minnesota, Minneapolis, MN
cThe Ohio State University College of Medicine, Columbus, OH
dUniversity of South Florida Morsani College of Medicine, Tampa, FL

Abstract
Background: Topical minoxidil (TM) has been a cornerstone in treating various hair loss disorders, while low-dose oral minoxidil (LDOM) is emerging as an effective alternative. Despite their widespread use, there is a notable gap in the literature regarding their use in treating scarring alopecia.
Objective: This study evaluates the efficacy and safety of TM and LDOM in managing scarring alopecia.
Methods: A systematic literature search identified relevant studies on TM and LDOM use in central centrifugal cicatricial alopecia, frontal fibrosing alopecia, lichen planopilaris, and traction alopecia. Key metrics included disease stabilization, hair thickness improvement, hair regrowth, and side effect profiles.
Results: Analysis of the selected studies revealed mixed outcomes. Most participants experienced benefits in terms of disease stabilization and hair regrowth with TM and LDOM. The majority of cases reported good tolerability of the treatment, although some side effects were noted.
Conclusion: TM and LDOM show promise in scarring alopecia treatment, demonstrating benefits in disease stabilization and hair regrowth. Despite these positive indications, the variability in results and reported side effects underline the need for further research to establish their consistent efficacy and safety profiles in scarring alopecia treatment.

J Drugs Dermatol. 2024;23(3):146-151     doi:10.36849/JDD.7743

INTRODUCTION

Topical minoxidil (TM) has been widely used to treat various hair loss conditions since it was first approved in the United States in 1986.1 More recently, low dose oral minoxidil (LDOM) has been increasingly utilized to treat scalp hair loss. This is partly due to its convenience and possible higher bioavailability in its active form (minoxidil sulfate) as it is more efficiently metabolized in the liver rather than the hair follicle with TM.2,3

While both LDOM and TM are being prescribed for both scarring and non-scarring alopecia, only TM is currently approved by the Food and Drug Administration (FDA) in the United States. Furthermore, the approved indication is androgenetic alopecia, which is a non-scarring alopecia. LDOM has not been studied or reviewed by the FDA as a treatment for hair disorders.  Additionally, most studies of LDOM or TM have focused on non-scarring alopecias such as alopecia areata and androgenetic alopecia.3

Scarring alopecia is responsible for approximately 10 to 30% of hair loss cases.4,5 Unlike non-scarring alopecias, hair follicles can be irreversibly damaged in scarring conditions by the destruction of stem cells in the hair bulge region, which warrants prompt and proactive treatment to reduce disease activity and restore hair thickness and density as much as possible.5,6 

TM and LDOM are frequently prescribed to patients with scarring alopecia based on extrapolated data from patients with non-scarring hair loss and anecdotal clinical experience. Multiple small retrospective studies report the safety and efficacy of TM and LDOM in the management of scarring alopecias but no comprehensive review of such data has been published. Here, we review oral and topical minoxidil for the management of scarring alopecia. 

MATERIALS AND METHODS

A comprehensive literature search across the PubMed, Embase, and Web of Science databases was performed to identify