[Coexistence of polymyalgia rheumatica with ankylosing spondylitis: A case report].

Ankylosing spondylitis is a chronic inflammatory disease that affects the spine and peripheral joints. Polymyalgia rheumatica is an inflammatory disease characterized by aching and prolonged morning stiffness mainly in the shoulder and pelvic girdles. Many other diseases may mimic polymyalgia rheumatica, and thus differential diagnosis is predominantly required. A wide variety of diseases, including spondyloarthropathies, may present polymyalgia-like symptoms, and two diseases rarely coexist. We present a case of a 54-year-old man who had been followed-up for ankylosing spondylitis and presented with pain in the shoulder and pelvic girdles, restricted movement, and morning stiffness for 2 months. Physical examination revealed that the pain was located mostly in the shoulder and pelvic girdles. In addition, increased erythrocyte sedimentation rate revealed the coexistence of the two diseases. Corticosteroid treatment dramatically improved the patient's symptoms and supported the diagnosis. This case demonstrated that ankylosing spondylitis may present polymyalgia-like symptoms, and the two diseases may rarely coexist in the elderly. The coexistence of these two diseases has been rarely reported in literature. Accurate diagnosis of the two diseases is essential for improving the patient's symptoms and quality of life.