Understanding RA Nodules
One symptom of rheumatoid arthritis not often discussed is rheumatoid nodules. These nodules are often left out of the conversation because they don’t occur for every patient. Instead, they only affect those who have the most severe form of the disease, around 20 percent of patients.
Those prone to developing nodules typically have a positive rheumatoid factor and may also have lung disease and inflamed blood vessels as a result of their RA.
Rheumatoid nodules are also often seen in patients who take methotrexate to control their disease and currently around eight percent of people on the drug will develop nodules.
Despite this, the number of people developing nodules in conjunction with their RA has been reduced in recent years along with the number of people who have developed lifelong deformities as a result of the illness. This is all largely thanks to advances in modern medicine and early intervention, both of which help control the disease and its activity much better than in the past.
What Are RA Nodules?
Rheumatoid nodules are made of inflammatory tissue and grow underneath the skin. At the center of each nodule is fibrinoid necrosis (or the death of cells that occur when complexes of antigens and antibodies deposit themselves in the walls of arteries). Small nodules have one center whilst larger nodules can have several centers. These nodules are hard to the touch, but are not sensitive nor are they painful (unless they occur somewhere sensitive).
They are typically found on joints, mostly on the fingers and elbows and places that are prone to injury. However, they can occur anywhere on the body and sometimes can be found on the back of the heel, penis, vulva, back, scalp, hips, bridge of the nose, or in the lungs and organs.
Of the internal organs, they can be found on the lining of the lungs, pancreas, vocal cords, trachea, kidneys, heart, in the breasts, liver, muscles, whites of the eyes, tendons and covering of the heart. Basically, they can occur almost anywhere, though they typically are located on or around joints affected by RA. Sometimes the centers of the nodules “feed” into the joint and contain synovial fluid.
Who Gets RA Nodules?
It is very rare for RA nodules to present themselves at the initial stages of RA. Usually, they are experienced by people who have had RA for quite a long time and may already be experiencing joint degeneration, though studies show that 11 percent of people have RA nodules at the time of diagnosis of their disease. Men are more prone to the nodules than women and certain genes and haplotypes can make one more vulnerable.
Around 75 percent of patients with RA-associated Felty syndrome will develop these nodules. Those with juvenile RA typically don’t typically develop the nodules, but that is not a hard and fast rule. Up to 10 percent of children with RA will develop them. Around 40 percent of people with a positive rheumatoid factor will also have such nodules.
Next page: what rheumatoid nodules look like, when to see a doctor, and RA nodule treatment options.