A case of post-streptococcal reactive arthritis in which lesions were detected with [18F]-fluorodeoxyglucose positron emission tomography-CT imaging and magnetic resonance imaging.

A 55-year-old man with lumbago and polyarthralgia was admitted to our hospital. Laboratory data showed elevated levels of anti-streptolysin O and C-reactive protein. Throat swab culture revealed beta-hemolytic streptococcal infection. Magnetic resonance imaging detected effusion of the lumbar bone and the left hip joint. Positron emission tomography-computed tomography (PET-CT) demonstrated increased fluorodeoxyglucose activity in the bilateral shoulder and hip joints and the interspinal ligament between L2 and L3. He was diagnosed as having post-streptococcal reactive arthritis (PSReA) and treated with amoxicillin hydrate. Polyarthralgia improved and did not relapse. To our knowledge, no results of PET-CT have previously been reported in patients with PSReA. We propose that PET-CT might be a useful tool for diagnosing PSReA.