Pericarditis With Cardiac Tamponade Mimicking Yellow Nail Syndrome in a Patient With Rheumatoid Arthritis and a Paucity of Joint Symptoms.

Pericarditis is a cardiac disease that commonly manifests with rheumatoid arthritis, and its complications are related to rheumatoid arthritis disease activity. The diagnosis can be complicated in patients with multiple extra-joint complications of rheumatoid arthritis. We report a case of pericarditis in an 82-year-old woman with few joint symptoms who was admitted to the hospital due to worsening edema of the lower legs and dyspnea, which progressed to cardiac tamponade. The patient presented with gradual onset of edema of both lower limbs and bilateral pleural effusion and was initially diagnosed with yellow nail syndrome. Ultimately, the patient was diagnosed with rheumatoid pericarditis due to a rapid increase in pericardial effusion. She was treated with non-steroidal anti-inflammatory drugs (NSAIDs) and colchicine; however, the symptoms were progressive and required pericardiocentesis. After pericardiocentesis, the patient responded well to NSAIDs and colchicine, and systemic edema was relieved. This case highlights the fact that pericarditis associated with rheumatoid arthritis is not necessarily related to the severity of joint symptoms. Moreover, it can be difficult to differentiate pericarditis from multiple other diseases, such as yellow nail syndrome, in patients with rheumatoid arthritis who mainly have extra-articular symptoms.