Subclinical vasculitis in polymyalgia rheumatica.

Polymyalgia rheumatica (PMR) is an inflammatory condition of the aging population characterised by pain, stiVness, and symmetrical involvement of shoulder and pelvic girdles. It has been proposed that the primary site of disease may reside outside the synovial joint, 2 but its aetiopathogenesis remains ill understood. There is good indirect evidence that vasculitis is important in the pathogenesis of PMR, based on observations from the closely related disease, giant cell arteritis (GCA). Many patients with GCA have PMR-like symptoms and the converse is also true. One of the characteristics of PMR is its dramatic response to moderate doses of corticosteroid treatment. However, a subset of patients responds inadequately to treatment or has diYculty with dose reduction, the basis for which is not well defined. We report here the case of a patient with PMR which was diYcult to treat who was found to have underlying vasculitis on magnetic resonance imaging (MRI), a finding which explains the requirement for the higher dose of steroids.