Diagnosis of Felty Syndrome prior to onset of Rheumatoid Arthritis

Abstract Felty Syndrome is the triad of rheumatoid arthritis, neutropenia, and splenomegaly. The cause of Felty Syndrome is unknown, but neutropenia is thought to be due to a disruption in the balance between granulocyte production and removal. There is splenomegaly due to sequestration of faulty blood cells, fostering an extra-hematopoietic site. Felty Syndrome usually presents many years after diagnosis of rheumatoid arthritis and affects 1–2% of rheumatoid arthritis cases. There have been only 2 documented cases of Felty Syndrome occurring prior to the onset of rheumatoid arthritis making it a rare presentation but should be on the differential diagnosis. The medical management of Felty Syndrome includes treating the underlying cause of Rheumatoid Arthritis with systemic steroids and disease modifying anti-rheumatic drugs (DMARDs) such as methotrexate. For Felty syndrome that is refractory to medical therapy as in this case, splenectomy is usually successful. In this case presentation, this patient presented with splenomegaly and neutropenia but had not had a diagnosis of rheumatoid arthritis. The patient later tested positive for anti-CCP antibody, confirming a diagnosis of rheumatoid arthritis. Days after initial admission, the patient had onset of wrist swelling, likely from the rheumatoid arthritis. This case was complex and multiple therapies were trialed, but eventually the patient underwent a splenectomy. In conclusion, Felty Syndrome, although rare in patients with years of rheumatoid arthritis, should be considered in patients who present with splenomegaly and neutropenia and do not have a known diagnosis of rheumatoid arthritis. If caught and treated early, splenectomy may be avoided and the joint damage from rheumatoid arthritis halted.