Pulmonary function in scleroderma.

Pulmonary function tests were performed in 45 patients with scleroderma. Thirteen patients (29%) were found to have restrictive disease, 12 patients (27%) were found to have obstructive disease, and 19 patients (42%) had small airway disease (SAD). Smoking did not seem to be a factor underlying either obstructive or small airway disease in these patients. A low diffusing capacity was most common in patients with restrictive disease and rarely the only abnormality in pulmonary function. SAD was usually found in patients who had normal chest radiographs and no pulmonary symptoms and was often the only abnormality. SAD is therefore an early and sensitive indicator of pulmonary involvement in scleroderma.