Jeff F. Wang

Agminated Papules and Pustules on the Flank—Quiz Case

A 41-year-old man presented with a 5-month history of progressively “rough skin” on his face. He had also developed a painful hemorrhagic lesion on his legs, a fever, and an 8-kg weight loss over the past 6 weeks. Physical examination revealed yellowish filiform follicular spicules with a horny appearance on the face, predominantly on the nose and ears (Figure 1 and Figure 2) but also on the scalp and upper trunk area. Retiform purpura and localized necrotizing livedo were also present on both legs. Laboratory tests showed an elevated level of C-reactive protein (34 mg/L [to convert to nanomoles per liter, multiply by 9.524]; reference range, 0-6 mg/L) and normocytic anemia (hemoglobin, 11.3 g/dL [to convert to grams per liter, multiply by 10.0]; reference range, 13.4-17.0 g/dL); electrolyte levels and liver and renal function test results were normal. Serum protein electrophoresis detected a visible paraprotein band, and serum immunoelectrophoresis revealed an IgGmonoclonal gammopathy. A skin biopsy of cutaneous spicules on the back was performed (Figure 3). What is your diagnosis?