A 61-year-old man presented with 3 weeks of shortness of breath and cough productive of occasional brown sputum. His medical comorbidities included Crohn colitis, deep vein thrombosis and pulmonary embolism on chronic anticoagulation, obstructive sleep apnea, obesity, impaired fasting glucose, depression, and latent tuberculosis status post 9 months of isoniazid. For the past year, his Crohn disease treatment regimen included methotrexate, and he received his first dose of ustekinumab 6 weeks before presentation. He was also being treated with an albuterol inhaler as needed, citalopram, folic acid, metformin, warfarin, and iron supplementation. He was diagnosed with community-acquired pneumonia 2 weeks prior and subsequently treated with levofloxacin. However, after finishing antibiotics he was still feeling unwell and had home oximeter readings in the low 80s. On physical exam at the time of presentation, he was alert and oriented and responding appropriately to questions. He had dry oral mucosa, regular rate and rhythm without murmurs, and no lower-extremity edema on cardiac exam. He was noted to be tachypneic and had bibasilar and right midfield crackles, but no significant respiratory distress at rest. His abdomen was soft and nontender. There were no motor or sensory abnormalities noted. Initial laboratory values showed an elevated lactate of 3.2 mmol/L (0.5-2.2 mmol/L), leukocytosis of 13.9×109/L (3.4-9.6×109/L), eosinophilia of 1.21×109/L (0.03-0.48×109/L), elevated C-reactive protein of 205 mg/L (≤ 8 mg/L) and erythrocyte sedimentation rate of 40 mm/1 h (0-22 mm/1 h). Chest radiograph revealed consolidation throughout the left mid and lower lung with new consolidation in the right upper lung and right lower lung. 1.What would be the next best step in managing this patient?a.

Prescribe an additional 7-day course of levofloxacin

b.

Prescribe 5-day course of prednisone

c.

Obtain QuantiFERON Gold testing

d.

Conservative treatment with close outpatient follow-up

e.

Obtain chest computed tomography (CT) scan