Pulmonary infiltrates in an elderly man

An 80-year-old man presented with subjective fever, chronic cough occasiona lly producing scant yellow sputum, retrosternal pleuritic pain, and dyspnea on walking one block. Since symptom onset three months earlier, he had los t 20 pounds; he had had two loose stools a day, fatigue, malaise, and anore xia but not hemoptysis, nausea, vomiting, hematemesis, hematochezia, or mel ena. Re denied paroxysmal nocturnal dyspnea or orthopnea. As far as could b e ascertained, he not recently been exposed to tuberculosis or any other in fectious disease. He had previously been seen at another clinic and had com pleted a 10-day trial of erythromycin (500 mg po q12h) without apparent cha nge ire symptoms.