Rheumatoid arthritis patients with peripheral blood cell reduction should be evaluated for latent Felty syndrome: A case report.

Rationale: Felty syndrome is a rare and life-threatening type of rheumatoid arthritis (RA).

Patient Concerns: A patient with RA had skin rash and subcutaneous hemorrhage, with a significant decrease in blood hemoglobin (Hb), white blood cell count (WBC), and blood platelet count (BPC).

Diagnoses: The patient had a history of RA, splenomegaly, decreased Hb, WBC, BPC, and normal immunological indexes, combined with a series of bone marrow related tests and genetic tests.

Interventions: She was given high-doses of glucocorticoids intravenously, followed by oral prednisone and cyclosporine maintenance therapy.

Outcomes: Her symptoms were resolved within 2 weeks after the start of immunosuppression. After 2 weeks of discharge, the Hb, WBC, BPC basically returned to normal, and prednisone gradually decreased.

Lessons: Felty syndrome is a rare complication of RA. Reductions in Hb, WBC, BPC, and subcutaneous hemorrhage should be considered strongly as the possibility of Felty syndrome. Multi-disciplinary diagnosis and related tests of bone marrow and genes are helpful for diagnosis and correct treatment.