Practice question

A 62-year-old woman presents with a 6-month history of progressive bilateral shoulder and hip girdle pain and stiffness, worse in the mornings and lasting over an hour. She also reports feeling generally unwell and fatigued. Examination reveals reduced active range of motion in the shoulders and hips due to pain. Inflammatory markers are raised: ESR 70 mm/hr, CRP 65 mg/L. What is the most likely diagnosis?