To compare diagnostic performance of traditional vertical section technique, horizontal section technique and modified Ho-Vert technique for classical lichen planopilaris.

Clinical data were collected from patients with classical lichen planopilaris in Department of Dermatology, The Affiliated Wuxi People′s Hospital of Nanjing Medical University from January 1st 2015 to January 1st 2019. With the help of dermoscopy, 2 scalp specimens were obtained from each patient and sliced horizontally and vertically respectively by using modified Ho-Vert technique. The horizontal and vertical sections were read separately or simultaneously, and histopathological changes were observed.

Totally, 21 patients with classical lichen planopilaris were enrolled into this study, including 15 males and 6 females. Their age was 50.0 ± 13.6 years, and the average course of disease was 18 months. The patients mainly presented with multifocal or confluent patchy hair loss, and scalp atrophy, perifollicular hyperkeratosis, loss of follicular ostia, fibrous white dots and orbit sign were observed. On the horizontal sections, lichenoid lymphocytic infiltration around the infundibulum and isthmus of hair follicles and follicular micro-scars could be observed in all patients, and the dermo-epidermal interface could be seen in 7 patients. On the vertical sections, lichenoid lymphocytic infiltration around the infundibulum and isthmus of hair follicles only could be observed in 9 patients, follicular micro-scars could be seen in 4, and the dermo-epidermal interface could be observed in all patients. Moreover, the detection rates of interfollicular interface dermatitis, follicular keratotic plugs, lymphocytic infiltration around sebaceous glands, atrophy or disappearance of sebaceous glands and inflammatory infiltration around hair follicle bulbs were significantly different between the horizontal and vertical sections. In combination with clinical manifestations, 7 patients could be exactly diagnosed with lichen planopilaris according to findings from horizontal sections, and 9 could be diagnosed exactly according to findings from vertical sections, while 21 could be diagnosed exactly according to histopathological findings from both horizontal and vertical sections.

With the help of dermoscopy, modified Ho-Vert technique can improve the efficacy of pathological diagnosis of classical lichen planopilaris, by multidimensionally showing histopathological changes.

Lichen planus; Alopecia; Hair follicle; Dermoscopy; Modified Ho-Vert technique; Hair pathology