[Visceral leishmaniasis mimicking Felty's syndrome in rheumatoid arthritis treated with methotrexate and etanercept].

Visceral leishmaniasis (VL) is a chronic parasitic disease caused by pathogens of the genus Leishmania, which can mimic numerous diseases. The leading symptoms of VL (splenomegaly, pancytopenia, fever) can be misinterpreted, especially if autoantibodies are detected, and lead to the misdiagnosis of an underlying rheumatic disease (e.g. systemic lupus erythematosus, Felty's syndrome). Proinflammatory cytokines such as tumour necrosis factor alpha (TNF-α) play an important role in infection control. In this context, there are increasing reports of VL as an opportunistic infection during treatment with anti-TNF‑α agents. A case of VL mimicking Felty's syndrome in a patient with rheumatoid arthritis treated with methotrexate and etanercept is presented.