The diagnostic diversity of polymyalgia rheumatica (PMR) can easily be obscured by the widespread use of corticosteroids (CSs) early in the disease course. This study observed the course of PMR without CSs and determined whether alternative medication could be useful.

Seventy patients with new-onset PMR comprised phase 1. Eight were removed with specific diagnoses (four with giant cell arteritis [GCA]). The remaining 62 were treated with nonsteroidal anti-inflammatory drugs (NSAIDs) alone until enough time had elapsed to ascertain whether their PMR had evolved into another rheumatologic inflammatory condition. Hydroxychloroquine (HCQ) was then added to their regimen. Twenty-five additional patients with PMR comprised phase 2. Twenty-two were immediately treated with HCQ prior to the anticipated disease progression.

In phase 1, 52/62 developed synovitis in multiple other joints 9 months from PMR onset; 48/52 received HCQ, and 42/48 (87.5%) achieved complete remission. In phase 2, during HCQ induction, 21 patients developed similar synovitis; after 6 months of HCQ use, 80% achieved remission. In 73/95 (77%), a definite diagnosis of rheumatoid arthritis (RA) could be made on average 8.5 months from PMR onset. Only 12/95 (13%) stayed true to form with their PMR and did not develop another specific diagnosis.

In this study, true PMR was infrequent in the absence of GCA. PMR in most patients evolved into seronegative RA, which was dramatically responsive to HCQ use. Treatment of acute PMR with HCQ was a rational alternative to CS use even if progressive additive synovitis had not yet occurred.