Abstract
A 93-year-old woman was admitted to our hospital because of fever. Radiographic findings revealed accumulation of pleural fluid. Moreover, blood tests revealed inflammation, lymphopenia, hypocomplementemia, positive for anti-nuclear antibody, and elevated anti-DNA antibody level. Therefore, the patient was diagnosed with pleuritis associated with systemic lupus erythematosus (SLE). Administration of prednisolone 20 mg/day resulted in a marked improvement in fever, pleuritis, and laboratory findings. We report a case of very-late-onset SLE that occurred at the age of 93.