Felty syndrome (FS), also known as ''super rheumatoid'' disease, is a severe form of rheumatoid arthritis (RA), characterized by a triad of RA, splenomegaly and neutropenia, resulting in susceptibility to bacterial infections. The disease is MONDO_0007603 (Felty syndrome). Also known as: Felty's syndrome, rheumatoid arthritis with splenoadenomegaly and leukopenia, splenomegaly-neutropenia-rheumatoid arthritis syndrome.