Remitting seronegative symmetrical synovitis with pitting edema syndrome: case report of an atypical presentation of a rare syndrome and literature review

Abstract

Abstract Background Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) is a rare syndrome. The following case shows an atypical course of the disease with successful treatment. In addition, the accompanied review highlights current findings in the pathogenesis and treatment. Clinicians should be aware of the differential diagnosis of RS3PE syndrome. Case presentation A 67-year-old female patient with recurrent, asymmetric, and painful swelling of both hands with pitting edema, predominantly affecting the dorsal right hand, presented at our in-patient clinic. Over the years of her disease, first diagnosed as rheumatoid arthritis and then psoriatic arthritis, prednisolone treatment had the most favorable effects over various disease-modifying antirheumatic drugs. Subsequent diagnostic evaluation confirmed RS3PE syndrome, a rare inflammatory disorder primarily affecting the elderly population. Manifesting as symmetrical joint inflammation of small joints with pitting edema, RS3PE syndrome typically onsets suddenly and may be accompanied by systemic symptoms like fever, fatigue, and weight loss. Although the precise etiology remains enigmatic, both the innate and the adaptive immune system seem to play a pathogenic role. Treatment is conventionally based on prednisolone, which effectively mitigates symptoms. Ultimately, RS3PE was diagnosed in the context of psoriatic arthritis without dermatological or nail involvement. Given the unusual presentation marked by female gender, asymmetry, and prolonged and extensive disease with various prior treatments and in the context of psoriatic arthritis, a tumor necrosis factor alpha inhibitor was initiated in addition to low-dose prednisolone resulting in clinical remission for the first time. Conclusions In conclusion, the aforementioned atypical manifestation highlights the significance of including RS3PE syndrome as a potential differential diagnosis, particularly in instances where specific diagnostic criteria for rheumatoid arthritis, polymyalgia rheumatica, or psoriatic arthritis are absent. RS3PE responds well to the administration of prednisolone. In refractory cases, a therapeutic trial with tumor necrosis factor alpha inhibitors can be conducted.

Keywords

• RS3PE
• Psoriatic arthritis
• Synovitis
• Tenosynovitis