Diffuse rash in a man with paraproteinemia

A 56-year-old man presents with diffuse pruritic papules involving the upper body, with nose and forehead thickening. Over the past 2 years, he has been evaluated by multiple specialists for dysphagia, reflux, chronic kidney disease, hypertension, and dyspnea on exertion. Examination results are significant for generalized firm, fleshy, dome-shaped papules of several millimeters in diameter, on his forehead, ears, neck, ...