Rheumatoid nodules are firm lumps that develop under the skin. They are a symptom that is unique to rheumatoid arthritis and usually occur near joints affected by the condition.
Rheumatoid nodules are a complication of rheumatoid arthritis, though not all people with the condition will develop nodules. Genetic factors are also thought to influence their development.
Rheumatoid arthritis is an autoimmune disease, which means it causes a person's immune system to attack healthy tissues in the body. Rheumatoid arthritis attacks healthy joints, causing swelling, pain, and sometimes difficulty with movement.
Over time, the joints may change shape, which makes movement painful. Most people with rheumatoid arthritis experience symptoms on both sides of the body.
Rheumatoid nodules are firm lumps under the skin. They do not change color or bleed and do not resemble other bumps on the skin, such as pimples. Instead, they look like firm, round lumps.
The nodules can cluster in groups or appear alone. They are more common on areas such as the hands, heels, and elbows, but any part of the body affected by rheumatoid arthritis can develop rheumatoid nodules. They are also common at pressure points.
Rheumatoid nodules are not usually painful, though pain is possible. In some people, the skin over the nodules becomes infected or develops ulcers. This can cause severe pain and require prompt treatment.
Some nodules may disappear over time while others will grow larger once they have established. It is impossible to predict how individual rheumatoid nodules will change.
People with poorly controlled or advanced rheumatoid arthritis may be at a higher risk of developing rheumatoid nodules.
Rheumatoid nodules may also indicate that a person is at risk of other health problems. People with rheumatoid nodules are more vulnerable to vasculitis, an inflammation of blood vessels that can be painful and even life-threatening.
A doctor may, therefore, advise a person to monitor carefully any nodules, even if they cause no other symptoms.
Rheumatoid arthritis is the primary cause of rheumatoid nodules, but some people with the disease are more susceptible to nodules than others. Rheumatoid nodules are also a sign of inflammation and heightened immune system activity.
A protein called rheumatoid factor appears to be linked to rheumatoid nodules and is produced by many people with rheumatoid arthritis.
High rheumatoid factor levels may be the most significant risk factor for rheumatoid nodules. About 40 percent of people with high levels of rheumatoid factor develop nodules.
Doctors still do not fully understand rheumatoid nodules and cannot predict who will develop them.
Some risk factors make rheumatoid nodules more likely. These include:
- Taking methotrexate or other arthritis drugs: Some people taking methotrexate develop a condition called
methotrexate-induced accelerated nodulosis, which causes nodules on the feet, hands, and ears.
- Trauma near a pressure point: People are more likely to develop rheumatoid nodules on pressure points. Experiencing a cut or bruise on those areas increases the likelihood of developing a rheumatoid nodule.
- Having severe rheumatoid arthritis: People with more serious symptoms are more likely to develop nodules. This may be because people with an advanced condition may also have high levels of rheumatoid factor.
- Smoking: Some studies suggest that people who smoke may be more vulnerable to developing rheumatoid nodules.
Unless rheumatoid nodules cause pain or other symptoms, they do not usually need treatment. Instead, the goal of treatment should be to manage symptoms of the underlying disease.
Numerous treatments for rheumatoid arthritis can help, including:
- Disease-modifying anti-rheumatic drugs (DMARD) to slow the progression of rheumatoid arthritis. One group of DMARDs called biologics is especially effective. Some research suggests the biologic called rituximab may be the best to treat nodules.
- Physical therapy to retain mobility and reduce pain.
- Painkilling medications, such as non-steroidal anti-inflammatory drugs (NSAIDs).
- Steroid medications, such as prednisone. Steroids can reduce the inflammation that causes pain and other symptoms.
Nodules that are painful or present a cosmetic concern can be surgically removed. However, as nodules usually respond to other arthritis treatments, the risk of surgery may outweigh the benefits of waiting for these to work.
Furthermore, a doctor will not often recommend surgical removal of a nodule because they frequently return.
Injecting rheumatoid nodules with steroids may improve symptoms, but this also has risks. An injection creates a wound that can become infected. The risks and benefits can be discussed with a doctor, and someone should only consider injections when nodules are painful or reduce mobility.
Infections related to rheumatoid nodules require prompt treatment, which can include intravenous or oral antibiotics. In some cases, an infection might need to be drained, or the nodules may need to be removed.
It is not possible to completely prevent rheumatoid nodules in people with rheumatoid arthritis. However, proper management of rheumatoid arthritis can help. To prevent rheumatoid nodules, people with rheumatoid arthritis should:
- quit or avoid smoking
- take medications as prescribed
- promptly report new or worsening symptoms to a doctor
- make lifestyle changes to increase mobility
By managing rheumatoid arthritis well, people can help eliminate rheumatoid nodules and some of the other symptoms of the disease.