Cutaneous T-cell lymphoma in erythrodermic cases may be suspected on the basis of scalp examination with dermoscopy.

Erythrodermic variants of cutaneous T-cell lymphoma (CTLC) are one of the case of erythroderma. The aim of the study was to assess the value of scalp dermoscopy in differentiation between erythrodermic CTCL, psoriasis, and atopic dermatitis. A total of 76 patients were included into the study (16 patients with erythrodermic CTCL, 20 patients with psoriatic erythroderma, 20 with erythrodermic atopic dermatitis, and 20 healthy volunteers). The most common trichoscopic features of erythrodermic CTCL were: numerous pili torti, numerous broken hairs, white thick interfollicular bands, and patchy hyperpigmentation of the background. They were observed in 81% (13/16), 75% (12/16), 56% (9/16), and 37.5% (6/16) of patients with CTCL, respectively (p < 0.001). Other specific features of erythrodermic CTCL were 8-shaped hairs (19%; 3/16) and visible anagen bulbs (12.5%; 2/16) (p < 0.05 and p = 0.052, respectively). The most common vascular pattern of erythrodermic CTCL was perifollicular arrangement of glomerular (50%; 8/16; p < 0.001) or linear vessels (31%; 5/16; p < 0.05). Follicular spicules-like scaling was pathognomonic for erythrodermic CTCL (12%, 2/16) although its presence did not reach statistical significance (p = 0.052). In conclusion, the characteristic trichoscopic findings of erythrodermic CTCL are numerous pili torti, eight-shaped hairs, thick white interfollicular bands, color heterogeneity of the background and perifollicular arrangement of vessels.