TY - JOUR T1 - Ankylosing spondylitis presenting with enthesitis at an uncommon site and fever of unknown origin JF - BMJ Case Reports JO - BMJ Case Reports DO - 10.1136/bcr-2019-230113 VL - 12 IS - 8 SP - e230113 AU - Naoki Kanda AU - Koichi Takeda AU - Shuji Hatakeyama AU - Masami Matsumura Y1 - 2019/08/01 UR - http://casereports.bmj.com/content/12/8/e230113.abstract N2 - A 58-year-old man presented with a 2-month history of arthralgia and bilateral temporal region pain, and a 1-month history of fever. He had had refractory neck pain since his 20s. Reduced cervical and lumbar mobility was observed. Radiographs of cervical and thoracic vertebrae disclosed syndesmophytes. Pelvic radiographs showed sclerosis in the right sacroiliac joint and ankylosis in the left sacroiliac joint. MRI with contrast enhancement showed enthesitis in the upper extremities and enhancement in the bilateral temporal muscle, which indicated enthesitis of temporal muscle. He was diagnosed with ankylosing spondylitis based on the limitation in mobility of the lumbar spine and radiographic findings. To the best of our knowledge, this is the first report describing enthesitis of the temporal muscle. This case highlights that ankylosing spondylitis can be accompanied with enthesitis at the temporal muscle and fever of unknown origin at the initial presentation. ER -