Updates in the Interpretation of Alopecia Biopsies

This article reviews best practices and high-yield advances in the pathologic interpretation of alopecia. It emphasizes the use of horizontal sectioning and biopsy optimization utilizing trichoscopy within watershed zones of alopecia. The evolving understanding of sebaceous gland atrophy is reviewed, and the paucifollicular unit is highlighted as a diagnostic feature of traction alopecia. Attention is focused on the underrecognized fibrosing alopecia in a pattern distribution and the classification of alopecic and aseptic nodules of the scalp. Finally, this article underscores the prevalence of multifactorial alopecia and the need for integrated clinical-pathologic correlation to improve diagnostic accuracy and patient outcomes.