Clinical Features
Even relatively brief asbestos exposures can result in clinically significant
pulmonary disease decades later. Despite instituting protective
measures for workers in the late 20th century, new cases of asbestosis
continue to be diagnosed. This emphasizes the importance of a thorough
occupational history when evaluating a patient with dyspnea.15-18
Patients most frequently seek medical attention because of gradual and
progressive dyspnea on exertion. They may also complain of a dry cough.
Chest pain or tightness is also described in advanced cases. A cough
productive for sputum and associated with wheezing is more frequently
seen in patients with concomitant chronic obstructive pulmonary disease
rather than asbestosis alone.1,6 Physical examination reveals fine endinspiratory
crackles at the bases. These crackles may progress to all lung
fields and continue throughout inspiration as the disease advances.
Clubbing of the fingers is reported and associated with severe disease.
Severe pulmonary fibrosis may progress to right heart failure that can
result in cyanosis, jugular venous distention, hepatojugular reflux, and
edema.15,18
Pulmonary function testing classically demonstrates a restrictive ventilator
pattern with decreased lung volumes. Forced vital capacity and total
lung capacity are typically the volumes most affected. The forced vital
capacity decrease correlates with increasing radiographic evidence of
fibrosis on chest x-ray. In addition, there is evidence of diminished gas