[Remitting seronegative symetrical synovitis with pitting edema. One case report].

Background: RS3PE (remitting seronegative symmetrical synovitis with edema and pitting) is a rare entity of unknown etiology that has been related to genetic predisposition due to the presence of HLA-A2 in 50% of cases and less frequently HLA-B7. Its pathogenesis is unknown, but it has been related to growth factors, and some mediators (TNF, IL-6). It is common in elderly people and the course of this illness presents with acute symmetrical polyarthritis, accompanied by edema in hands and feet. The diagnosis requires a high index of suspicion and to differentiate it from other entities such as rheumatoid arthritis, complex regional pain syndrome, rheumatic polymyalgia, in addition to ruling out malignant neoplasms, since there are many reports of its association with both solid and hematological neoplasms, being of bad prognosis when there is association. When there is no association with cancer, it responds well to the use of low doses of steroids and its prognosis is usually favorable. Clinical case: 80-year-old woman with an acute onset with polyarthralgia, functional limitation associated with pitting edema in hands and feet. After approaching the patient and ruling out associated neoplasms, it was diagnosed RS3PE. It was managed with prednisone, observing a good response, with remission of the manifestations at 6 weeks and subsequent suspension of the steroid. Conclusions: RS3PE is a rare entity, and a high index of suspicion is required for the diagnosis. A complete approach is important to rule out cancer in patients affected with this syndrome. Prednisone continues to be the best therapeutic option.