A 45-year-old man complains of painless nodules that appeared on the skin of his limbs and on the small of his back. The nodules have a tendency to grow peripherally and merge together. The disease onset was 2 years ago, family history states that his father had a similar skin condition. Objectively, the pathologic elements manifest as drop shaped and coin-shaped nodules and plaques, covered in white scales. Make the provisional diagnosis: