Vivek Medepalli

A 59-year-old male presents to the ED with abdominal pain, hematuria, and rectal bleeding for the 5 days. His symptoms have been associated with unintentional weight loss, intermittent fevers, skin rash, and fatigue over the past 3 months. He has a past history of hepatitis B, hypertension, diabetes, and hyperlipidemia. Vital signs include blood pressure 162/103 mm Hg (last measured 118/82 5 months ago, per records), HR 101, RR 18, SpO2 98% on room air. Exam is notable for generalized abdominal tenderness, guaiac positive stool, and generalized purpuric rash over bilateral lower extremities. Labs demonstrate Cr 2.9 (baseline 1.1) and elevated ESR and CRP. What is the most likely diagnosis, and what are the next steps in management?