I have a bump on my elbow that my doctor says is a rheumatoid nodule. What is a rheumatoid nodule?
A rheumatoid nodule is a bump in the skin that is found in approximately 25% of people with RA. In fact, identifying a rheumatoid nodule in a person who has recently developed arthritis can help a doctor to make the diagnosis of RA.
These bumps are found below the surface of the skin and can be moved with your fingers in most cases. Rheumatoid nodules can be as small as a pea or as large as a golf ball. The size of the nodules can change during the course of the disease, getting larger as the activity of RA increases but then regressing when the disease is quiescent. They tend to be firm, but are not rock hard and are usually not tender to the touch. These nodules are found at pressure points on the body such as the elbows and heels as well as points where the skin is irritated or traumatized, such as the knuckles of the hands and fingers and along the back of the forearm.
The exact cause of rheumatoid nodules is unknown. Some experts have theorized that they occur as a result of a minor injury to the blood vessels in the skin. This injury triggers an abnormal immune response, which in turn causes inflammation and swelling.
Despite their name, rheumatoid nodules are not found exclusively in individuals with RA. Identical nodules are sometimes seen in patients with systemic lupus erythematosus (SLE), rheumatic fever, and other diseases. They can even be caused by the presence of foreign bodies in the skin, such as splinters.
Most patients with RA don't get rheumatoid nodules; those patients who do develop these nodules tend to have more serious RA. The nodules tend to occur after the disease has been present for several years and are usually found in patients who have a strongly positive rheumatoid factor test and those with more active disease.
Patients who are treated with the medication methotrexate have noted that their nodules increase in number and appear on the fingers. These new nodules can be painful and limit hand function. Antitumor necrosis factor medications such as infliximab (brand name: Remicade) can also cause nodules to decrease in size and number, though not always.
Rheumatoid nodules are clinical predictors of joint erosion and extra-articular (non-joint-related) complications of RA involving the lungs or eyes. An inflammation of the blood vessels known as rheumatoid vasculitis can occur in patients with these nodules, for example. The presence of rheumatoid nodules often suggests a need for more aggressive treatment of the underlying RA to prevent complications. Some physicians have noted that fewer patients are developing rheumatoid nodules these days thanks to the modern aggressive treatment approaches used in RA.
For the most part, rheumatoid nodules are painless and cause few problems. Nevertheless, larger nodules can cause some problems:
- Pain—if they are irritated by rubbing against clothes, shoes, or jewelry, or if they become infected
- Limited joint mobility—if they are large or too close to the joint or tendon
- Neuropathy—if they press on nearby nerves
- Ulceration—if the skin overlying the nodules breaks down, causing bleeding and pain and opening up a portal for bacteria to enter and cause an infection
When ulcerations become large, deep, and long-lasting, they can result in the formation of a fistula. A fistula is an abnormal passage between the skin's surface and the inside of a joint.
Most doctors caution patients to leave rheumatic nodules alone, unless they are painful, become infected, limit the motion of a joint, or are cosmetically unacceptable. Nodules can be removed surgically, but they tend to reoccur in as little as a few months when they are present over an area of repeated trauma. Most dermatologists recommend treating nodules by injecting them with steroids. This treatment has the advantages of being able to reduce the size of the nodule while avoiding surgery and subsequent scarring. Rheumatoid nodules occasionally resolve without medical or surgical intervention.
I have rheumatoid nodules in my elbows and knuckles. The nodules have increased. Hands are stiff and painful in the morning. Soaking in hot water or using a heating pad relieves stiffness and pain.