Fusobacterium nucleatum endocarditis mimicking polymyalgia rheumatica.

A case of Fusobacterium nucleatum endocarditis in an 80-year-old man is reported. The patient presented with a headache and nonspecific musculoskeletal symptoms and was misdiagnosed as having polymyalgia rheumatica. The diagnosis of bacterial endocarditis was delayed because of an insidious presentation, typical in infections with low virulence micro-organisms. The musculoskeletal symptoms, unresponsive to protracted corticosteroids, completely resolved with intravenous ampicillin treatment. Rheumatologic symptoms may hinder the correct diagnosis of subacute infective endocarditis. An atypical evolution of a common rheumatic disorder such as polymyalgia rheumatica should alert physicians to the possibility of bacterial endocarditis.