Scleroderma lung disease.

Pulmonary involvement is second in frequency only to esophageal involvement as a visceral complication of systemic sclerosis (SSc) and has surpassed renal involvement as the most common cause of death. Interstitial lung disease and pulmonary vascular disease, particularly pulmonary arterial hypertension, are the most commonly encountered types of lung involvement. Chronic aspiration, airway disease, neuromuscular weakness, extrinsic pulmonary restrictive pathology, pleural effusions, pneumothorax, and lung cancer cause clinically significant disease and occur commonly enough to be routinely considered in the assessment of the SSc patient with respiratory symptoms. Affected patients have a significantly worse prognosis than patients with SSc who are free of pulmonary involvement.