Rheumatoid nodules are firm, flesh-coloured lumps that grow under the skin. The nodules grow close to the affected joints. Rheumatoid nodules can be as large as a walnut or as small as a pea.
20% to 35% of adults with rheumatoid arthritis (RA) get rheumatoid nodules. Sometimes the nodules are movable. Or, they can be firmly connected to tendons or fascia (fat) under the skin.
Rheumatoid nodules are found at pressure points, including:
The nodules can also form on the vocal cords, causing hoarseness. Rheumatoid nodules may appear in the lungs, heart and other internal organs.
Many people with RA have no pain or symptoms with the nodules, but some patients find the nodules painful. Sometimes rheumatoid nodules interfere with daily activities, put pressure on nerves and limit movement. Rheumatoid nodules in areas such as the heart and lungs may affect organ function.
What are the causes of rheumatoid nodules?
Rheumatoid nodules usually occur in patients with severe RA. Nearly all RA patients with nodules test positive for rheumatoid factor.
Rheumatoid factor is positive in 70% to 80% of people with RA. Studies show that when RA is linked with a positive rheumatoid factor test, it may indicate more aggressive disease.
Other factors may increase the chance of RA nodules. One study found that cigarette smoking increases nodules in patients with RA. Methotrexate, a commonly used RA drug, has also been linked to increased development of rheumatoid nodules.
Are there treatments for rheumatoid nodules?
Sometimes disease-modifying anti-rheumatic drugs (DMARDs) can reduce the size of RA nodules. But patients who take methotrexate may develop an increase in size and number of nodules. If nodules are thought to be a result of methotrexate treatment, a change in medication regimen may help; however, this decision must be carefully made on an individual basis.
Injections of corticosteroids may help shrink nodules. Sometimes surgery is necessary if rheumatoid nodules become infected or cause severe symptoms.
Seeing your doctor regularly is important to avoid serious problems with rheumatoid nodules.