[Verified Answer]: A 28-year-old man comes to the emergency…

A 28-year-old man comes to the emergency center complaining of 6 days of fever with shaking chills. Over the past 2 days, he has also developed a productive cough with greenish sputum, which occasionally is blood streaked. He reports no dyspnea, but sometimes he experiences chest pain with deep inspiration. He does not have headache, abdominal pain, urinary symptoms, vomiting, or diarrhea. He has no significant medical history. He smokes cigarettes and marijuana regularly, drinks several beers daily, but denies intravenous drug use. On examination, his temperature is 39,1oC (102.5F), heart rate is 109 bpm, blood pressure is 128/76 mm Hg, and respiratory rate is 23 bpm. He is alert and talkative. He has no oral lesions, and funduscopic examination reveals no abnormalities. His jugular veins show prominent V waves, and his heart rhythm is tachycardic but regular with a harsh holosystolic murmur at the left lower sternal border that becomes louder with inspiration. Chest examination reveals inspiratory rales bilaterally. On both of his forearms, he has linear streaks of induration, hyperpigmentation, and some small nodules overlying the superficial veins, but no erythema, warmth, or tenderness. Laboratory examination is significant for an elevated white blood cell (WBC) count at 17,500/mm3, with 84% polymorphonuclear cells, 7% band forms, and 9% lymphocytes, a hemoglobin concentration of 14 g/dL, hematocrit 42%, and platelet count 189,000/mm3. Liver function tests and urinalysis are normal. Chest radiograph shows multiple peripheral, ill-defined nodules, some with cavitation. Questions What is the most likely diagnosis? What is your next step?