Question: A 52-year-old man presents to the emergency room with a painful skin rash. He has large painful purple lumps on his legs. Some of these have now turned from purple to black. They are extremely painful and prevent him from sleeping. He denies fevers, chills, weight loss, dyspnea, abdominal pain, or diarrhea. His past medical history includes HIV infection complicated by end-stage renal disease from focal segmental glomerulosclerosis. He has been on dialysis for the last three years. His medications include bictegravir, emtricitabine, tenofovir, and vitamin D supplements. Temperature is 98.1°F, pulse is 95/min, blood pressure is 114/70 mmg, respiratory rate is 16/min, and oxygen saturation is 97% on room air. Skin examination is notable for violet nodules on the bilateral lower extremities, as well as areas that have turned black (see image below). The lesions extend from the lower extremities up to the abdomen and lower back. Which of the following is the most likely diagnosis? Need Assignment Help? (A) Bacillary angiomatosis (B) Calciphylaxis (C) Kaposi sarcoma (D) Psoriasis (E) Tertiary syphilis