Pleuro-Pericardial Inflammation and Effusion: A Rare Acute Initial Presentation of Rheumatoid Arthritis

Background: Rheumatoid arthritis is a systemic inflammatory arthritis characterized by joint pain and morning stiffness. The affected joints are typically symmetrically affected, and given the inflammatory nature of this condition, patients often present with warmth and erythema around affected joints as well as fatigue. Extra-articular manifestations, especially pleuro-pericardial inflammation, are rare initial presentations, although may be seen in advanced or undertreated disease. Case Presentation: We describe a case of a rheumatoid arthritis presenting atypically in a middle-aged male who came to the emergency department complaining of diffuse muscle pain and swelling in the distal extremities. Cardiac ultrasound revealed pleuro-pericardial inflammation and effusions. Myositis and infectious causes were ruled out and bilateral hand x-rays did not show erosions or any evidence of arthritic changes. All rheumatological auto-antibodies were negative except for rheumatoid factor and anti-cyclic citrullinated peptide (CCP) and a diagnosis of rheumatoid arthritis was made. The patient was started on prednisone with excellent response. Conclusions: This case highlights that rheumatoid arthritis can uncommonly present initially with extra-articular manifestations that are often manifested in advanced disease. Typically, extra-articular manifestations, especially those as severe as this patient’s, occur with untreated, advanced disease and could accompany extensive arthritic joint changes. Thus, it is important to have an understanding of rare, atypical presentations of rheumatoid arthritis so that a high index of suspicion can be maintained to make the diagnosis and initiate treatment in a timely manner.