What Are Rheumatoid Nodules?


We get a lot of questions about nodules on MyRACentral  - specifically what are they? What causes them? Can you treat them? Etc. - so we decided to ask Dr. Joan Merrill, a rheumatologist at the Oklahoma Medical Research Foundation, to give us the basics.

What are nodules?
Nodules look like bumps under the skin, and can be painful, red and sore, says Dr. Merrill, but they can also be painless and can come on any part of the body.  Though, usually they appear under the skin, in places where we put weight on our bodies, such as shoulders or elbows, they can also develop in the lining of the brain, or in the heart.

“They are fairly benign things,” says Dr. Merrill, but they are inflammatory nodules with central necrosis, or dead cells at the center of the nodule.

These nodules can be small or large, and a person could have one or two, or many of them. It’s all variable, and dependent upon the person, she says.

Who is more likely to get them?
People who have more severe rheumatoid arthritis or people who have certain kinds of genetic markers for RA are more likely to develop nodules. This occurs in about 20 percent to 25 percent of RA patients, says Dr. Merrill.

“It’s the same pathology as you get in the joint of an RA patient - it’s inflammation,” she says. “So, it’s somebody born with a certain set of genes, but nobody knows the exact set of triggers that cause nodules.”

Can people who do not have RA get nodules?
Sometimes you can get them without RA, says Dr. Merrill, but most people are rheumatoid arthritis patients.

Can you treat nodules?
If you have RA, and you notice you have a nodule, you can just wait until your next visit to your rheumatologist, says Dr. Merrill, as treatments are not typically permanent anyway.

If you have them taken off surgically, or injected with a steroid, you will typically get more nodules, she says.

Are there complications to having nodules?
Aside from pain from putting your weight on the nodules (if they are on your elbows or shoulders, etc.), the other complication is possible infection. “It’s basically a cyst, and if they get infected, they can get nasty,” she says.

Can we predict who will get nodules?
Unfortunately, we don’t know the bio-marker to predict who will get nodules, says Dr. Merrill. “I wish we knew more, I wish we could prevent that from happening, but we just don’t know enough.”