A subtle brown halo around hair follicles on trichoscopy, often discussed in androgenetic alopecia.
The peripilar sign is a brownish halo around follicular openings seen on trichoscopy. It is often described in androgenetic alopecia and may reflect perifollicular inflammation or pigmentation around miniaturising follicles. It is not diagnostic on its own, but it can add weight to a pattern hair loss diagnosis when combined with hair shaft diameter diversity, increased vellus hairs and a typical distribution. Its presence may also help identify areas of active change for monitoring.
DermNet trichoscopy of generalised non-cicatricial hair loss: https://dermnetnz.org/topics/trichoscopy-of-generalised-noncicatricial-hair-loss ; Anastassakis, Androgenetic Alopecia From A to Z, Vol. 1: https://doi.org/10.1007/978-3-030-76111-0