The Facts About Felty Syndrome

If you have long-standing rheumatoid arthritis, you are at higher than normal risk of developing Felty syndrome (also called Felty's syndrome), a rare and complex condition that compromises your immune system and puts you at further risk of contracting an infectious disease.

Three factors contribute to a diagnosis of Felty syndrome: the presence of rheumatoid arthritis, an enlarged spleen, and a low white blood cell count due to cell destruction. Low levels of white blood cells result in decreased immunity and a greater chance of recurring infections. In a July 2011 issue of Current Opinion in Hematology, researchers at Penn State Hershey Cancer Institute in Pennsylvania proposed a link between Felty syndrome and a specific form of leukemia, indicating that the two conditions are virtually the same with respect to physical manifestations, laboratory results and genetic markers.

The symptoms of Felty syndrome may include:

  • decreased appetite
  • eye discharge and discomfort
  • fatigue
  • joint stiffness, pain, swelling and deformity
  • pale skin (due to anemia) or skin darkening in patches
  • recurring infections
  • unintentional weight loss

In very rare cases, symptoms of Felty syndrome appear without arthritis. If, upon examination and laboratory testing, a doctor finds evidence of enlarged spleen, low white blood cell count and high rheumatoid factor in the blood, researchers at Mount Sinai School of Medicine in New York say that Felty syndrome is present and predicts the onset of rheumatoid arthritis.

It's currently unclear how to prevent Felty syndrome, but treatment is available in the form of medications that suppress an overactive immune system. In some cases, doctors may decide that the best treatment option is surgery to remove the spleen. But there's some good news, too. Some people with Felty syndrome have few symptoms, and some cases have been known to go into spontaneous remission. And, although more than 95 percent of people with Felty syndrome also have rheumatoid arthritis, only 1 percent of people with rheumatoid arthritis actually develop this condition, according to research published in Best Practice and Research: Clinical Rheumatology.



Balint, GP and Balint, PV; "Felty's Syndrome." Best Practice and Research: Clinical Rheumatology. 2004 Oct; 18(5):631-45 Web. 28 Dec 2011

Liu X, Loughran TP; "The Spectrum of large Granular Lymphocyte Leukemia and Felty's Syndrome." Current Opinions in Hematology. 2011 July; 18(4):254-9. Web 28 Dec 2011

MedlinePlus: Felty Syndrome. Web 28 Dec 2011

National Institutes of Health Office of Rare Diseases Research: Felty's Syndrome Web 28 Dec 2011