'Black dots' seen under trichoscopy are not specific for alopecia areata.

BACKGROUND

'Black dots' are macrocomedo-like round structures localized to the follicular ostium, and are considered a specific trichoscopic feature of alopecia areata (AA).

AIM: To characterize specific features of 'black dots', and assess their possible presence in common hair and scalp disorders.

METHODS

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.

RESULTS

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.

CONCLUSIONS

Black dots are not specific for AA, and may be present in other hair and scalp diseases.