A dermoscopy of linear unilateral syringoma has never been described in the English literature. The authors report the case to elucidate the dermoscopic features of syringoma. Clinical, dermoscopic and pathological features of a 38-year-old Japanese female case of linear unilateral syringoma on the left upper arm were described and compared with those of lichen planus linearis. Although the clinical appearance of linearly arranged dusky erythemas in the present case was quite similar to that of lichen planus linearis, dermoscopy did not show Wickham's striae but rather homogeneous light brown pigmentation with multifocal whitish areas and a delicate pigment network at the periphery. Dermoscopy might be helpful to differentiate linear unilateral syringoma from lichen planus linearis.
Keywords: Wickham's striae.; dermoscopy; lichen planus linearis; unilateral linear syringoma.