['Videodermatoscopy is a non-invasive technique that allows in vivo skin observation at high magnifications.', 'The goal of this study was to determine if videodermatoscopy enhances diagnostic capability beyond standard clinical observation in three series of patients: one group of patients with overt alopecia areata (AA), one with overt androgenetic alopecia (AGA), and one with hair loss with no apparent diagnostic features.', 'The first group consisted of 200 patients affected by acute (140 patients) and chronic (60 patients) AA, and the second group of 100 patients affected by AGA. In both groups, the clinical diagnosis was confirmed by pull tests and trichograms. The third group consisted of 50 patients with clinically undifferentiated hair loss. In all groups, videodermatoscopy was performed at magnifications ranging from 20x to 600x.', "In acute AA (n = 140), three videodermatoscopy patterns were identified, characterized by: (i). 'exclamation point' and/or 'cadaveric' hairs (n = 62); (ii). 'vellus' hairs, in some cases with increased proximal shaft thickness and pigmentation (n = 38); and (iii). coexistence of all the features from (i). and (ii). [n = 40]. In chronic AA (n = 60), in those cases who were recently converted to chronic form from acute AA (n = 35), videodermatoscopy showed a scalp skin that appeared smooth and thin, with evident follicular openings. In cases of long-standing chronic AA (n = 25), hair follicle openings appeared to be obstructed by keratotic plugs. However, whether the two follicular patterns were related to disease duration or to some unknown factors is unclear. In some patients with chronic AA, videodermatoscopy also revealed hair regrowth, which appeared either as homogeneous, indicating early disease remission (upright 'vellus' hairs), or as sparse, thin, and twisted vellus hairs that were usually lost in a few weeks time. In AGA patients, videodermatoscopy observation allowed an accurate assessment of the ratios of miniaturized to normal hairs, a finding that was interpreted as a prognostic feature. Interestingly, videodermatoscopy clearly demonstrated the hair abnormalities corresponding to both diseases in those patients with concomitant causes of hair loss, as we observed in five patients simultaneously affected by AA and AGA. In the third group, videodermatoscopy allowed identification of early or minimal forms of AA (n = 20), AGA with mild hair loss of the centro-parietal area of the scalp (n = 20), and scarring alopecia (n = 10)."] Does videodermatoscopy enhance diagnostic capability in some forms of hair loss?