Pulmonary sarcoidosis.

Sarcoidosis is a granulomatous disease of unknown cause, occurs worldwide and has a highly variable prevalence. The disease is typically dominant in the lungs, although it can affect virtually any organ and is unpredictable in its clinical course. The severity of pulmonary sarcoidosis ranges from incidentally discovered radiographic abnormalities in asymptomatic patients to a chronic progressive disease that is refractory to treatment. Mortality from sarcoidosis appears to have increased in the past three decades, with respiratory failure being the most common cause of sarcoidosis-related death. Pulmonary fibrosis, extensive disease on high-resolution chest CT, impaired lung function, and pulmonary hypertension are well established predictors of poor clinical outcomes. In patients who need systemic therapy to control their disease, corticosteroids are the most commonly used first-line treatment, with antimetabolites generally representing an alternative for patients who are unresponsive to corticosteroids or who cannot tolerate them. Indeed, corticosteroid therapy is associated with toxic effects that correlate with both the cumulative dose and duration of treatment. The scarcity of truly effective therapies and shortage of reliable predictors of the unpredictable development of disease in individual patients greatly contribute to making sarcoidosis such a difficult disease to manage.