History and Physical Examination
History
Because the development of asbestosis is dose dependent, symptoms appear only after a latent period of 20 years or longer. This latent period may be shorter after intense exposure.
Dyspnea upon exertion is the most common symptom and worsens as the disease progresses. Patients may have a dry (ie, nonproductive) cough. A productive cough suggests concomitant bronchitis or a respiratory infection. Patients may report nonspecific chest discomfort, especially in advanced cases.
Physical examination
Rales are the most important finding during examination. Persistent and dry, they are described as fine cellophane rales or coarse Velcro rales. The rales are best auscultated at the bases of the lungs posteriorly and in the lower lateral areas.
Initially, physicians hear rales in the end-inspiratory phase. In advanced disease, however, rales may be heard during the entire inspiratory phase. Occasionally, the presence of rales precedes radiographic finding abnormalities and pulmonary function test abnormalities. Rales are not to be expected in all patients; one third of them may not have this symptom.
Finger clubbing is observed in 32-42% of cases. This finding is not necessarily related to the severity of disease.
Reduced chest expansion in advanced disease correlates with restrictive ventilatory impairment and reduced vital capacity. In advanced disease, patients may show the following signs associated with cor pulmonale: cyanosis, jugular venous distention, hepatojugular reflux, and pedal edema.
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Asbestos pleural plaques.
