Conflicting Reports Regarding the Histopathological Features of Androgenic Alopecia: Are Biopsy Location, Hair Diameter Diversity, and Relative Hair Follicle Miniaturization Partly to Blame?

• Published in: Clinical, cosmetic and investigational dermatology Vol. 14; pp. 357 - 365
• Main Authors: English, Robert, Ruiz, Sophia
• Format: Journal Article
• Language: English
• Published: New Zealand Dove Medical Press Limited 01.01.2021; Taylor & Francis Ltd; Dove; Dove Medical Press
• Subjects: Alopecia; androgenic alopecia; Baldness; Biopsy; Change blindness; fibrosis; hair diameter diversity; Hair loss; Hard disks; Histochemistry; Hypothesis; Inflammation; Investigations; Prostaglandins; androgenic alopecia; hair diameter diversity; prostaglandins; fibrosis; inflammation
• ISSN: 1178-7015; 1178-7015
• DOI: 10.2147/CCID.S306157

Despite decades of study, debate persists over the role of inflammation, fibrosis, and prostaglandins in the histopathology of androgenic alopecia (AGA). This brief review proposes that inconsistent findings across histological studies are a consequence of three inadequately controlled variables: 1) biopsy location, 2) hair diameter diversity (HDD), and 3) relative hair follicle miniaturization (HFM) within and across subjects. We suggest new methodological considerations to improve AGA histopathological research, as well as a novel classification system to quantify HFM by its stages. Finally, we hypothesize a dynamic relationship between inflammation, fibrosis, and prostaglandin activity dependent on relative HFM.