Temporal triangular alopecia: significance of trichoscopy in differential diagnosis.

Background: There are only two case reports in literature regarding the trichoscopic features of temporal triangular alopecia (TTA). Differential diagnosis of other types of localized alopecia such as alopecia areata is necessary in some cases.
Objective: To evaluate the potential benefit of trichoscopy in the clinical diagnosis of TTA.
Methods: Nine patients with a clinical diagnosis of TTA were included in the study. Trichoscopic examination was performed by a polarized-light handheld dermatoscope with a 10-fold magnification. The images were obtained by a digital camera that produced imagery with a 3-fold optical zoom.
Results: Short vellus hairs, vellus hair length diversity and white hairs were encountered in all subjects, while white dots, honeycomb pigment pattern, arborising red lines and epidermal scale were noted in 22%-33% of them. None of the cases showed trichoscopic features such as tapering hairs, yellow dots or loss of follicular openings.
Conclusion: We suggest that it seems possible to differentiate TTA by a handheld dermatoscope. Short vellus hairs with length diversity and white hairs in the absence of diagnostic features of other types of localized alopecia should be considered in favour of TTA.
(© 2014 European Academy of Dermatology and Venereology.)