A 76-year-old Japanese woman was referred to our clinic with fever and right wrist pain of four days duration. Her right wrist was markedly swollen and tender (Picture 1A). A wrist X-ray was normal and musculoskeletal ultrasonography indicated active synovitis without crystal deposition (Picture 1B). On close examination, we identified a bite with an eschar on her left foot (Picture 2). A real-time polymerase chain reaction (PCR) analysis was performed on DNA isolated from a skin tissue samples following the method described in a previous report (1), and a Rickettsia japonica infection was thus identified. Treatment with minomycin (200 mg/day) was effective. Her fever improved the next day, and the arthritis also dramatically improved on the 7th day with no other treatments (Picture 1C). Japanese spotted fever (Rickettsia japonica infection) causes symptoms of fever and intense myalgia (2), but there are no reports of arthritis associated with this infection. It is therefore important to consider the possibility of Rickettsia japonica infection in patients with arthritis.
Picture 1.
Picture 2.
The authors state that they have no Conflict of Interest (COI).
References
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