Nothing about sarcoidosis is easy. First identified in 1877, it is quite common. In the United States, lifetime risk is 2.4% and 0.85% for African American persons and White persons, respectively. Still, it remains an enigma. Despite study of its genetics and immunopathology, we don't know its cause. Diagnosis is challenging because noncaseating granulomas, the tissue finding associated with sarcoidosis, aren't specific for the disease. With the exception of Löfgren syndrome, a well-described sarcoid presentation that portends an excellent prognosis, initial signs and symptoms are variable and disease course is unpredictable. Alas, because sarcoid affects the lungs in more than 90% of patients, the general pulmonologist is left carrying the bag as the "sarcoidologist."
The inherent heterogeneity of sarcoid makes it challenging to study. In the modern era of evidence-based medicine, it's hard to say much about it with certainty. The American Thoracic Society (ATS) is one of just a few, premier organizations that creates respiratory medicine guidelines. In 1999, they published a sarcoid consensus statementwith the European Respiratory Society (ERS), another outstanding and influential respiratory medicine organization, and the World Association of Sarcoidosis and other Granulomatous Disorders (WASOG). For the past 20 years, I've been referring trainees to this document for guidance on managing their patients with sarcoid.
