Valvulopathy and new onset psychosis in a patient with rheumatoid arthritis: a case to challenge the diagnosis of rhupus

Abstract

Rheumatologic disease includes a vast array of distinct diagnostic entities. Although clinical manifestations may differ, they all share a common inflammatory reaction driven by autoimmunity. Up to 25% of patients with pathognomonic clinical features remain undiagnosed due to paucity of standardized diagnostic criteria, and therefore the use of diagnostic classifications. Patients may present with clinical features of more than one rheumatologic condition, further complicating the diagnostic process. The advent of disease modifying anti-rheumatic drugs has revolutionised care of these patients in recent years, which place the burden firmly on accurate diagnosis. In this case report we present a young female with Rheumatoid Arthritis (RA) presenting with first onset psychosis, fever, oral mucosal ulceration and  echocardiographic findings of aortic valve thickening. These lesions may be in keeping with Libman-Sacks Endocarditis (LSE) or  rheumatoid valvulopathy. She was diagnosed with RA 3 years prior to presentation based on the American College of Rheumatology/ European League Against Rheumatism Collaborative Initiative (ACR/EULAR) classification criteria for RA. The patient met the diagnostic  classifications of both RA and Systemic Lupus Erythematosus (SLE) and a diagnosis of rhupus was postulated, however, she tested negative for anti-double stranded deoxyribonucleic acid (anti-dsDNA) and anti-Smith (anti- Sm) antibodies. This case illustrates the  complexity of diagnosis in rheumatology. RA and SLE are well defined rheumatological conditions, but result from different immunological processes and present with different clinical presentations. Rarely, features of both diseases present in the same patient, and classification criteria are met for both conditions. Rhupus is a condition which presents as an overlap between RA and SLE, and should be recognised as a unique clinical entity with a different clinical presentation, natural history, management and prognosis. This case represents a clinical entity with overlap features of RA and SLE, but lack the auto-immune markers typical of rhupus.