Less Common Respiratory Conditions: Sarcoidosis.

Sarcoidosis is a systemic condition characterized by formation of granulomas that can involve many organ systems, with the lungs and intrathoracic lymph nodes involved in more than 90% of cases. Sarcoidosis also can involve the cardiac, ocular, hepatic, dermatologic, and central nervous systems. The presentation of pulmonary sarcoidosis is nonspecific. Less than half of patients initially have respiratory symptoms and the disease often is detected as an incidental finding of lymphadenopathy on chest x-ray. However, lymphadenopathy can occur in many other conditions, ranging from tuberculosis to cancer, so sarcoidosis should be diagnosed only after excluding these other conditions. Typical granulomatous findings on lymph node biopsy can increase confidence in sarcoidosis diagnosis after the other conditions are excluded. However, there are three syndromes which, if present, are diagnostic of sarcoidosis: Lofgren syndrome, Heerfordt syndrome, and lupus pernio. The majority of sarcoidosis cases resolve spontaneously, so treatment typically is reserved for patients with progressive pulmonary or extrapulmonary involvement, specifically ocular, cardiac, or central nervous system. Systemic corticosteroids are first-line treatment. Second-line treatment with methotrexate or hydroxychloroquine is used if steroids are ineffective or to enable steroid tapering. Refractory disease should be comanaged with a sarcoidosis subspecialist.