Efficiency of Hair Detection in Hair-to-Hair Matched Trichoscopy

Oral Minoxidil vs Topical Minoxidil for Male Androgenetic Alopecia: A Randomized Clinical Trial

Importance

There has been increased interest in low-dose oral minoxidil for androgenetic alopecia (AGA) treatment. However, the efficacy of oral minoxidil for male AGA is yet to be evaluated in comparative therapeutic trials.

Objective

To compare the efficacy, safety, and tolerability of daily oral minoxidil, 5 mg, vs twice-daily topical minoxidil, 5%, for 24 weeks in the treatment of male AGA.

Design, Setting, and Participants

This double-blind, placebo-controlled randomized clinical trial was conducted at a single specialized clinic in Brazil. Eligible men with AGA aged 18 to 55 years classified using the Norwood-Hamilton scale as 3V, 4V, or 5V were included and randomized. Data were collected from January to December 2021, and data were analyzed from September 2022 to February 2023.

Interventions

Participants were randomized 1:1 into 2 groups: oral minoxidil, 5 mg, daily and topical placebo solution; or 1 mL of topical minoxidil, 5%, twice daily and oral placebo for 24 weeks.

Main Outcomes and Measures

The primary outcome was change in terminal hair density on the frontal and vertex regions of the scalp. The secondary outcomes were change in total hair density and photographic evaluation.

Results

Among 90 enrolled participants, 68 completed the study; of these, the mean (SD) age was 36.6 (7.8) years. A total of 33 participants were enrolled in the oral minoxidil group and 35 in the topical treatment group. Both groups were homogenous in terms of demographic data and AGA severity. For the frontal area, the mean change from baseline to week 24 between groups was 3.1 hairs per cm2 (95% CI, -18.2 to 21.5; P = .27) for terminal hair density and 2.6 hairs per cm2 (95% CI, -10.3 to 15.8; P = .32) for total hair density. For the vertex area, the mean change from baseline to week 24 was 23.4 hairs per cm2 (95% CI, -0.3 to 43.0; P = .09) for terminal density and 5.5 hairs per cm2 (95% CI, -12.5 to 23.5; P = .32) for total hair density. According to the photographic analysis, oral minoxidil was superior to topical minoxidil on the vertex (24%; 95% CI, 0 to 48; P = .04) but not on the frontal scalp (12%; 95% CI, -12 to 36; P = .24). The most common adverse effects in the oral minoxidil group were hypertrichosis (22 of 45 [49%]) and headache (6 of 45 [14%]).

Conclusions and Relevance

In this study, oral minoxidil, 5 mg, once per day for 24 weeks did not demonstrate superiority over topical minoxidil, 5%, twice per day in men with AGA.

Trial Registration

Brazilian Registry of Clinical Trials Identifier: RBR-252w9r.

Hair-to-Hair Trichoscopy: An Objective Method to Assess Effectiveness of Botulinum Toxin in a Clinical Trial for Androgenetic Alopecia

Introduction

Androgenetic alopecia (AGA) is the most common alopecia affecting both genders leading to a potential decrease in quality of life and self-esteem. A current concern in trichology is how to accurately measure clinical response in both daily medical practice and academic research. Hair-to-hair (H2H)-matching technology™ has recently emerged as a technique to evaluate variations in follicular units, hair shaft number, and thickness. This study aimed to describe the methodology employed in a clinical trial using this technology to test the efficacy of botulinum toxin (BT) for male AGA.

Methods

This pilot study is a triple-blind, randomized, split scalp, placebo-controlled clinical trial. Patients enrolled were submitted to injections half of the scalp with 50 IU of BT and the other half with 1 mL of normal saline as a control. The trial involved three visits (weeks 0, 12, and 24) and 8 global clinical photographs followed by H2H-matching trichoscopy were captured before the injections at each visit. Paired t test analysis was employed for matched pairs of the following parameters: total hair count, the total number of terminal hair strands, average shaft thickness, and the number of hairs lost or gained during each visit. Then, the software compared the differences between the two sides (BT vs. placebo) per scalp zone and a long time.

Conclusion

The combination of manually corrected image processing, follicular map, and H2H-matching technology™ appears to be the most precise way to evaluate changes in hair count and thickness over time. The design is reproducible and can help other researchers and dermatologists in their clinical practice to obtain reliable results in similar scientific research.