What is Felty's Syndrome?

Felty's Syndrome or Felty Syndrome is a rare disorder that may complicate the illness of those who have rheumatoid arthritis. Not all people with rheumatoid arthritis have or will develop Felty's Syndrome. Having two additional conditions identifies those that do: a very low white blood cell count, and an enlarged spleen, called splenomegaly.

Felty's Syndrome creates issues because the abnormally low level of white blood cells predisposes people to higher risk for infection. Those with Felty's Syndrome are more susceptible especially to pneumonia and skin infection. In fact some with Felty’s Syndrome may develop lesions on their legs, which can easily become infected. Additional symptoms of Felty's Syndrome include those associated with rheumatoid arthritis, high levels of fatigue, and loss of appetite.

Diagnosis for Felty's Syndrome has no single test. Instead, presence of these three conditions indicates Felty's Syndrome. Treatment tends to be based on the degree to which susceptibility to infection is present.

Some people with Felty's Syndrome have their spleen removed, as an enlarged spleen may lead to sudden rupture. Others with Felty’s syndrome may be treated with daily antibiotics. Sometimes doctors hesitate to use prophylactic antibiotics since this may lead to more antibiotic-resistant strains of bacteria like Methicillin-resistant staphylococcus aureus (MRSA).

Many people with Felty’s Syndrome may also receive weekly injections of granulocyte stimulating faction (GSF), which helps to stimulate the production of a certain form of white blood cells called granulocytes. This may only work when blood work shows that the granulocytes are in short supply. Doctors also focus on treating the symptoms of rheumatoid arthritis through a variety of medications.

Doctors also advise those with Felty’s Syndrome to get flu shots, and to be particularly vigilant during cold and flu season. They should generally avoid crowded areas during the winter months. Further, they should avoid contact with those who are actively sick.

Felty's Syndrome puzzles many researchers because the lack of white blood cells most often indicates inappropriate function of the bone marrow. This would suggest that a bone marrow transplant might prove useful. However, people with Felty’s Syndrome appear to have normally functioning bone marrow, initially producing enough white blood cells. The white cells are then attacked and destroyed by the body’s own immune response.

Only about 1% of people with rheumatoid arthritis develop Felty’s Syndrome. It tends to develop most often in people over 50. Some people may have Felty’s Syndrome but not be diagnosed because they have experience no symptoms of the disease.