A New Subtype of Lichen Planopilaris Affecting Vellus Hairs and Clinically Mimicking Androgenetic Alopecia

This document describes a new subtype of lichen planopilaris (LPP) that affects vellus hairs and clinically mimics androgenetic alopecia (AGA). The study found that in this new subtype of LPP, vellus hair follicles are decreased, perifollicular fibrosis and lichenoid lymphocytic infiltration are present, and only vellus hairs are selectively affected in histopathology. The authors had a large sample size and strict eligibility criteria to reduce selection bias. The study emphasizes the importance of biopsy in diagnosing cicatricial alopecia and the need for accurate differential diagnoses for AGA. The study concludes that further research is needed to investigate the diagnostic values of differentiating attributes and to design more efficient clinical decision steps.