A 53-year-old woman has persistent linear keratotic furrows localised to the first web space of both her hands. What is this skin condition?
A 53-year-old woman gave a four-year history of persistent linear keratotic furrows localised to the first web space of both hands. The rough keratotic ridges were limited to the medial aspect of her thumbs and lateral aspect of her index fingers at the junction of the ventral and dorsal skin of the hands. Skin biopsy showed a thick keratin layer, and the underlying dermis had broad bands of collagen and thickened elastic fibres, some of which were orientated towards the surface.