‘Black dots’ seen under trichoscopy are not specific for alopecia areata

Abstract

'Black dots' are macrocomedo-like round structures localized to the follicular ostium, and are considered a specific trichoscopic feature of alopecia areata (AA). To characterize specific features of 'black dots', and assess their possible presence in common hair and scalp disorders. In total, 107 patients with hair loss [30 with alopecia areata (AA), 37 with androgenetic alopecia (AGA), 17 with chronic telogen effluvium (TE), 23 with other hair and scalp diseases] and 93 healthy controls were examined, using a videodermoscope with 20-70 times magnification. There was a correlation between the black dots and the early acute phase of the various alopecia types with the presence of the black dots. Black dots were found in 11% (22/107) of patients with hair loss, including 53.3% (16/30) with AA; in 40% (2/5) of patients with severe chemotherapy-induced alopecia, and in 100% of patients with dissecting cellulitis of the scalp (n = 2), hypotrichosis simplex (n = 1), and congenital aplasia cutis (n = 1). No black dots were seen in patients with AGA or TE. Black dots are not specific for AA, and may be present in other hair and scalp diseases.