Into the Woods

A CLINICAL PROBLEM-SOLVING article by Nasia Safdar from University of Wisconsin–Madison.
A 79-year-old woman presented with a 1-month history of dyspnea and a cough productive of yellow sputum. She reported no chest pain, hemoptysis, night sweats, or fever.
Three months earlier, the patient had been clinically diagnosed with giant-cell arteritis. And she was placed on 40 mg of oral prednisone daily which she was still taking at the time the pulmonary symptoms developed.
The patient was retired and spent a great deal of time in the woods around her home in Wisconsin.
On physical examination, the patient was a thin, elderly woman in no acute distress.
The erythrocyte sedimentation rate was 117 mm per hour; C-reactive protein was 27 mg per deciliter. A chest radiograph revealed air-space opacity in the left upper lobe.
Several days after admission, repeated chest ray showed worsening disease.
Gram's staining of a sputum specimen revealed beaded, branching, gram-positive rods.
Correctly and efficiently diagnosing the cause of pulmonary disease in an immunocompromised patient is challenging. Knowledge of the rate of disease progression and the type of immune compromise is useful in the initial differential diagnosis. A detailed history to elicit epidemiologic exposures further refines the possible diagnoses. Finally, the pattern of lung involvement can also help narrow down the possible causes.