"Patient is a 49 year old male who p/w SOB x 3 days w/ cough. Denies fever/chills, no N/V.  Possible PNA. Diff dx includes COVID vs pneumonia vs COPD exacerbation." In the following statement, list which entities are present, absent, or possible? Do not include details. Write your response with exactly 4 paragraphs, separated with the markdown divider: ***.
user