Affiliation:
1. Department of Dermatology Tokyo Midtown Skin/Aesthetic Clinic Noage Tokyo Japan
2. Tokyo Midtown Center for Advanced Medical Science and Technology Tokyo Japan
3. Tokyo Midtown Clinic Tokyo Japan
Abstract
AbstractBackgroundDespite similarities in progressive miniaturization of hair follicles and transition of terminal hairs to vellus hairs, insufficient trichoscopic comparisons between male androgenetic alopecia (MAGA) and female pattern hair loss (FPHL) hinder our ability to select effective treatments.AimOur study aimed to explore gender‐specific trichoscopic characteristics of MAGA and FPHL, while formulating hypotheses regarding the progression of these conditions across clinical stages.MethodsWe classified 126 male MAGA subjects using Hamilton‐Norwood Classification and 57 FPHL subjects using adopted Sinclair Scale. Subsequently, we analyzed nine trichoscopic factors divided into three categories: hair‐diameter related, hair‐number per follicular unit related, and hair density related factors.ResultsOf the nine quantitative trichoscopic factors, hair‐diameter and hair‐number per follicular unit showed strong correlations with clinical stages in both genders. Hair density, a common trichoscopic factor for hair loss evaluation, weakly correlated with clinical stages in FPHL, but not at all in MAGA. In addition, MAGA was characterized by a progressive reduction in hair‐diameter, followed by a reduction in hair‐number per follicular unit. FPHL, on the contrary, showed the opposite progression.ConclusionsTrichoscopic factors vary with disease severity in a gender‐specific manner. Our research highlights that MAGA and FPHL involve two distinct streams: hair‐diameter decreasing by hair follicle miniaturization (Stream 1), and hair‐number per follicular unit decreasing by hair follicle tri‐lineage niche dysfunction (Stream 2). MAGA typically starts from Stream 1 to Stream 2, while FPHL starts from Stream 2. These diverse progression pathways underscore the importance of personalized treatment approaches.