Acute Onset Polyarthritis with Pitting Edema: Is it RS3PE?

Dear Editor, A 48-year-old female presented with pain and swelling in the bilateral proximal interphalangeal (PIP), metacarpophalangeal (MCP) and wrist joints for the past 20 days. It was acute in onset, severe in intensity to such an extent that she was unable to make a fi st. It was associated with acute onset of diffuse painful swelling over the dorsum of hands. History of morning stiffness was present, lasting up to 1 hour, and eases only slightly with the consumption of painkillers prescribed by a local general practitioner. On local examination, there was diffuse pitting and tender edema over both hands extending up to wrist, showing a ‘boxing glove’ appearance (Fig. 1A). A clinical provisional diagnosis of remitting seronegative symmetrical synovitis with pitting edema (RS3PE) was made. On investigation, it was found that the patient’s erythrocyte sedimentation rate (ESR) = 41 mm (>20 mm), C-reactive protein (CRP) = 24 (>5), rheumatoid factor (RF) = 85 (+ve) and anti-cyclic citrullinated peptide (anti-CCP) = 3.25 (-ve). X-ray of bilateral hands was normal without showing any evidence of erosions. Ultrasonography of hands reveals extensor tenosynovitis of bilateral hands. These gave a confused picture between rheumatoid arthritis (RA) and RS3PE. A diagnosis of RA was initially preferred, it being a more common disease and the patient had a positive RF. The patient was managed with disease-modifying antirheumatic drug (DMARDs) and low-dose prednisolone (20 mg daily). After 10 days, all her symptoms were completely resolved (Fig. 1B) and she stopped taking her medications. For the past 6 months, she had been completely asymptomatic without taking any medication. She had been continuously evaluated for any symptoms and signs of underlying malignancy and none have been reported so far.