A 62-year-old woman presented with a 2- to 3-week history of fatigue, nonproductive cough, dyspnea on exertion, and intermittent fever/chills. Her past medical history was significant for rheumatoid arthritis (RA) that had been treated with methotrexate and prednisone for the past 6 years. The patient was currently smoking half a pack a day with a 40-pack year history. The patient was a lifelong resident of Arizona and had previously worked in a stone mine.
On physical examination she appeared comfortable without any increased work of breathing. Her vital signs included a temperature of 36.6° C, a blood pressure of 110/54 mm Hg, a pulse of 90 beats/min, respirations of 16/min, and room-air oxygen saturation of 87%. Pulmonary examination revealed scattered wheezes with fine bibasilar crackles. The remainder of her physical exam was normal. Because she was hypoxic, she was admitted to the hospital.
At the hospital, a chest x-ray showed diffuse, bilateral interstitial changes (FIGURE 1). Laboratory tests revealed a white blood cell count of 13,800/mcL (normal: 4500-10,500/mcL) with 73% neutrophils (normal: 40%-60%), 3% bands (normal: 0-3%), 14% monocytes (normal: 2%-8%), 6% eosinophils (normal: 1%-4%), and 3% lymphocytes (normal: 20%-30%). Community-acquired pneumonia was suspected, and the patient was started on levofloxacin. Over the next 2 days, her dyspnea worsened. She became tachycardic, and her oxygen requirement increased to 15 L/min via a non-rebreather mask. She was transferred to the intensive care unit.