A 45-year-old man with good past health complained that he had itchy and dry skin, in particular, the lower limbs for about 3 to 4 years. Physical examination revealed dry rough skin and symmetrical scaling on both lower limbs. The scales were small, fine and polygonal in shape.

What could be the most probable diagnosis for this condition? *This image based case is from Docplexus editorial team for educative purpose only. Source: Haymarket