Very Late-Onset Systemic Lupus Erythematosus as Unusual Cause of Reversible Functional and Cognitive Impairments in an Octogenarian Patient.

While functional decline is a common syndrome in geriatric medicine, the diagnosis of the underlying disease can be complex. We present a case of very late-onset systemic lupus erythematosus with fever, arthritis, lymphadenopathy, sicca syndrome, pleurisy, renal impairment and reversible functional and cognitive impairments. Prompt improvement was observed on prednisolone and hydroxychloroquine. LEARNING POINTS: Systemic lupus erythematosus (SLE) rarely occurs in octogenarian patients.In such oldest old patients, SLE may predominantly present with subacute cognitive and functional impairments.Low-dose treatment (prednisolone 7.5 mg/day and hydroxychloroquine 5 mg/kg/day) can reverse all SLE manifestations within 1 month.