Common etiologies being common, a patient with these symptoms (cough, shortness of breath, chest discomfort and hemoptysis), even with history of sarcoidosis probably has a simple bronchitis and should be treated and evaluated as such. However, given that a sarcoid flare could present similarly if not exactly the same way, initiation of treatment with steroids to treat this should be considered at the time of ED evaluation or later if symptoms do not improve.
Source
King, T. MD. "Treatment of pulmonary sarcoidosis with glucocorticoids" Up to Date. Oct 2008.
King, T. MD. "Clinical manifestations and diagnosis of sarcoidosis" Up to Date. Oct 2008.