Trichoscopic features of androgenetic alopecia according to the basic and specific (BASP) classification: A retrospective observational study

This retrospective study involving 157 Korean participants (129 males, 28 females) analyzed 471 trichoscopic images to evaluate the correlation between trichoscopic features and the severity of androgenetic alopecia (AGA) using the BASP classification. The study found that trichoscopic scalp signs, such as vellus hair and single-hair follicular units, were significantly more prevalent in individuals with AGA compared to controls, and these signs increased with disease severity. The total hair count and multi-hair follicular units decreased as AGA severity increased. The study concludes that trichoscopy is a valuable tool for early detection and monitoring of AGA, with vellus hairs and changes in follicular unit composition serving as key indicators of disease progression. Limitations include its retrospective, single-centre design and the absence of hair shaft diameter measurements.