Rheumatoid Nodules

Overview

Rheumatoid nodules are firm lumps that develop under the skin in people who have rheumatoid arthritis (RA), an autoimmune disease in which the immune system attacks the joints. They are the most common skin-related feature of RA and tend to appear over areas of pressure or repeated friction, such as the elbows, the backs of the fingers, and the heels.

The nodules range from pea-sized to several centimeters across and are usually painless, although they can become tender or interfere with movement depending on their location. Their presence often indicates more active or longer-standing rheumatoid arthritis. While the nodules themselves are not dangerous, they are a sign of the underlying disease and occasionally cause complications when they form in awkward locations or over pressure points.

Symptoms

Rheumatoid nodules have several characteristic features:

• Firm, round, or oval lumps beneath the skin
• Usually skin-colored and not red or warm unless irritated
• Most often over the elbows, knuckles, forearms, heels, and other pressure points
• Generally painless, though they can be tender if pressed or rubbed
• May be movable under the skin or feel fixed to deeper tissue

People with nodules usually also have the joint symptoms of rheumatoid arthritis, such as swelling, stiffness (especially in the morning), and pain in the small joints of the hands and feet. Rarely, nodules form in internal organs such as the lungs.

Causes

Rheumatoid nodules form as part of the inflammatory process of rheumatoid arthritis. They are areas where immune cells and inflammatory tissue collect, often at sites of repeated pressure or minor injury, which may explain their typical locations over the elbows and other bony points.

The exact trigger is not fully understood, but nodules are strongly associated with the immune activity of RA. They are more likely in people who test positive for certain blood markers of rheumatoid arthritis, such as rheumatoid factor. In some cases, the medication methotrexate, used to treat RA, is linked to a particular pattern of small nodules, especially on the hands.

Risk Factors

Factors that make rheumatoid nodules more likely include:

• Having rheumatoid arthritis, especially when it is more severe or active
• A positive rheumatoid factor or other RA-related antibodies in the blood
• Longer duration of the disease
• Smoking, which is linked to more aggressive RA
• Treatment with methotrexate in some people
• Repeated pressure or friction over a body area

Nodules are uncommon early in the disease and tend to appear as rheumatoid arthritis progresses.

Diagnosis

Rheumatoid nodules are usually recognized by their typical appearance and location in someone already known to have rheumatoid arthritis. A clinician examines the lumps and reviews the person's joint symptoms and history.

When the diagnosis of RA is not yet established, blood tests for rheumatoid factor and anti-CCP antibodies, along with inflammation markers, help confirm the underlying disease. Imaging is occasionally used for nodules in unusual sites. A biopsy is rarely needed but may be done if the diagnosis is uncertain or another cause for a lump must be ruled out.

Treatment

Treatment focuses mainly on controlling the underlying rheumatoid arthritis, since well-managed disease often leads to fewer or smaller nodules. Approaches include:

• Disease-modifying medications: Drugs that suppress the overactive immune response and treat RA overall.
• Adjusting medication: If methotrexate appears to be driving nodules, a rheumatologist may modify the treatment plan.
• Local injection: A steroid injected into a troublesome nodule can sometimes shrink it.
• Surgical removal: Considered for nodules that are painful, become infected, limit movement, or are in an awkward location, though they can return.
• Pressure relief: Padding or footwear changes to protect nodules over pressure points.

Because nodules can recur, especially while the underlying disease remains active, ongoing rheumatology care is important.

Prevention

There is no guaranteed way to prevent rheumatoid nodules, but the following can reduce the chance or severity:

• Keeping rheumatoid arthritis well controlled with prescribed treatment
• Stopping smoking, which is linked to more severe RA
• Protecting pressure points such as the elbows and heels from repeated friction
• Attending regular reviews so disease activity and treatment can be adjusted

Good overall management of rheumatoid arthritis offers the best chance of limiting nodules and other complications.

When to See a Doctor

See a healthcare provider if you develop new firm lumps under the skin, especially over the elbows or other pressure points, particularly if you also have joint pain, swelling, or morning stiffness that could indicate rheumatoid arthritis. Early diagnosis and treatment of RA improve long-term outcomes.

Contact your provider promptly if a nodule becomes red, warm, painful, or starts to break down or drain, as this may indicate infection or skin breakdown that needs treatment. Your rheumatology team can also advise whether troublesome nodules should be injected or removed.

Related Topics

Frequently Asked Questions

References

1. American College of Rheumatology.
2. Mayo Clinic. Rheumatoid arthritis.
3. MedlinePlus, U.S. National Library of Medicine.