[A case of sarcoidosis presenting with high fever and rash progressing to acute respiratory failure].

A 66-year-old man who had been given a clinical diagnosis of vasculitis at another hospital after presenting with high fever and rash was admitted to our hospital for further examination following a relapse of fever during steroid reduction. The biopsy specimens of the leg with crusts showed the presence of epithelioid granuloma, and because of a negative tuberculin test, increased serum angiotensin converting enzyme (ACE) and lysozyme levels, and pulmonary Ga uptake, the patient was given a diagnosis of sarcoidosis. Although the patient had been treated on an outpatient basis following resolution of fever with NSAIDs and 5 mg prednisolone (PSL), he suffered acute respiratory failure during follow-up and required emergency admission. Chest CT revealed bilateral ground-glass opacity and pleural effusion, and serum ACE and soluble IL2R levels were significantly elevated. We diagnosed acute exacerbation of sarcoidosis and given high dose steroid therapy. The patient's symptoms, image findings, blood test results, and other findings promptly improved. Here we reported a highly unusual presentation of acute respiratory failure in sarcoidosis.