Absence of vellus hair in the hairline: a videodermatoscopic feature of frontal fibrosing alopecia

MADAM, Frontal fibrosing alopecia (FFA), generally considered a clinical variant of lichen planopilaris, is a female scarring alopecia characterized by progressive recession of the frontotemporal hairline (Fig. 1a), frequently associated with eyebrow loss. FFA typically, but not exclusively, affects postmenopausal women and is clinically characterized by perifollicular erythema, follicular hyperkeratosis and scarring, affecting mainly the frontotemporal hairline, although involvement of the parietal and occipital hairline and/or nonmarginal scalp may occur. In the early stages, the clinical findings may be subtle, making the diagnosis troublesome, prompting the need of a biopsy for histological examination. Dermatoscopy and videodermatoscopy (VD) of the scalp, also called trichoscopy, have been suggested as noninvasive diagnostic tools for the diagnosis and follow-up of different types of hair loss, including FFA. In a series of 19 patients with FFA, Rakowska et al. reported the absence of follicular openings in all cases, and the presence of perifollicular scaling in 15 cases, as the most frequent features, confirming the results of other case reports. However, according to our experience, the absence of follicular openings is sometimes difficult to identify, as brown halos (expression of inflammation) and/or white dots (expression of follicle fibrosis) may be misinterpreted as active follicles, and perifollicular scaling may be mild and often absent, especially in treated or remitting FFA. In order to evaluate the VD features of FFA, we carried out a retrospective analysis of VD images obtained from the hairlines of 34 women (mean age 52 2 years, range 36–79 years) affected by pathologically confirmed FFA exclusively involving the frontotemporal area, diagnosed in the dermatology departments of the universities of Catania and Miami from April 2009 to July 2012. VD examination was performed with a system allowing scalp observation at high magnification (20–1009) and in incident light, without the use of immersion oil (‘dry VD’). At the end of the study, the following VD features were observed: (i) perifollicular scaling in 27/34 cases, which was otherwise absent (four cases) or doubtful (three cases); (ii) absence of follicular openings in 22/34 cases, otherwise being present (one case) or doubtful (11 cases); (iii) brown halos/white dots in 15/34 cases; (iv) absence of vellus hairs in 32/34 cases (in the remaining two cases only a few isolated vellus hairs were detected); (v) pili torti in nine cases; and (vi) black dots/broken hairs in five cases. In our series of patients, the predominant VD pattern was therefore represented by the absence of vellus hairs (Fig. 1b), observed in almost all cases (94%). The presence of perifollicular scaling was observed in 79% of cases. Follicular openings were absent in 65% of cases; in most other cases (32%) this aspect was doubtful, due to the presence of brown halos and/ or white dots. Interestingly, perifollicular erythema has never been observed by VD, even if it was present at clinical examination in some cases. This might be due to the use in our study of dry VD, which enhances the visualization of vellus hair, but hampers the correct visualization of the vascular pattern. The results obtained from the patients with FFA were compared with those obtained from a series of 45 women, taken from our databases, affected by other types of hair loss involving the frontotemporal area. In Hamilton type androgenetic alopecia (14 patients) VD showed an increased presence of vellus hairs in the hairline, with an inversion of the ratio terminal/vellus (Fig. 2a). In ophiasic alopecia areata (16 patients), VD showed the presence of a variable percentage of exclamation-mark hairs, black dots, yellow dots and vellus hair (Fig. 2b). In traction alopecia (15 patients) vellus hairs were preserved (Fig. 2c). These results were comparable with those reported in the literature. The absence of vellus hair in the frontotemporal hairline in FFA has never been reported in previous studies, and it could be explained as follows. Vellus and terminal hairs in the hairline are typically observed in healthy scalp (Fig. 2d), with BJD British Journal of Dermatology