AbstractBackgroundThe sonographic characteristics of frontal fibrosing alopecia have been scarcely studied. The aim of this study was to perform a colour Doppler ultrasound evaluation in frontal fibrosing alopecia.Materials and methodsA cross‐sectional study including 99 women with frontal fibrosing alopecia and 40 control subjects was performed using ultrasound equipment with a lineal 18 MHz probe. Three areas were evaluated per patient: the alopecic area (a), the hairline implantation area (b) and healthy scalp (c). The diameter (cm) and flow (m/s) of the two most significant vessels were recorded.ResultsWith regard to the hairline implantation area, patients presented higher vessel diameter (0.127 cm vs 0.103 cm, P = .03) and vessel flow (8.183 m/s vs 7.670 m/s, P = .05) than the control group. Vessel diameter was higher in the healthy scalp area in patients than in the control group (0.088 cm vs 0.078 cm, P = .03).ConclusionPatients presented higher vessel diameter and flow in the hairline implantation area compared to the control group.