To determine the efficacy and safety of shoulder corticosteroid injections in polymyalgia rheumatica (PMR).
Twenty consecutive patients with active PMR were randomized into a 7 month, double blind, placebo controlled study. Patients received either bilateral shoulder injections of 40 mg of 6-methylprednisolone acetate or placebo (1 ml saline solution). Responders were treated weekly with the same regimen for a total of 4 bilateral injections and then followed for 6 months. Response was defined as a 70% reduction in visual analog scale (VAS) score for pain and for patient and physician global assessment, and duration of morning stiffness. Bilateral shoulder magnetic resonance imaging (MRI) was performed at different times to evaluate the response of lesions to therapy.
All 10 corticosteroid treated patients responded to the first injection with a significant reduction in duration of morning stiffness, VAS pain scale, patient and physician global assessment, erythrocyte sedimentation rate, and C-reactive protein. Interleukin 6 serum levels were significantly reduced after the 2nd injection. In 5 patients, the response persisted throughout the followup period. The other 5 withdrew within 4 weeks after the 4th injection due to recurrence of symptoms. None of the 10 patients of the placebo group responded to the first injection. The difference between the 2 groups was significant (p = 0.03). No side effects were recorded. MRI showed marked improvement of shoulder lesions one week after first injection and an almost complete resolution one week after last injection in the responders.
Shoulder corticosteroid injections seem to be an effective and safe therapy for PMR.