Rheumatoid nodules are soft tissue lumps that occur in 20-30% of rheumatoid arthritis (RA) patients. They may be found almost anywhere on the body, but are most often seen in areas where there are bony prominences. These include pressure points such as the elbow, back of the forearm, and knuckles of the hand. Sometimes they may occur on the back of the head or Achilles tendons.
Nodules usually occur in chronic active cases of rheumatoid arthritis, and are commonly associated with more severe joint deformity and serious disease. People with rheumatoid nodules often have very high levels of rheumatoid factor in the blood.
At a microscopic level, these nodules often contain the same types of cellular infiltrates as seen in the joints.
Patients with very serious RA may have problems in other organ systems. These are referred to as extra-articular (outside the joint) manifestations. These extra-articular areas include the lungs, eyes, skin, heart, brain, and blood vessels. Nodules may vary in size during the course of the disease process. With increasing severity of disease, the nodules may increase in size and in number.
Complications of rheumatoid nodules include a number of problems such as:
o increased pain due to pressure phenomena
o limited joint mobility due to size and location of the nodules
o nerve damage due to location of nodules
o ulceration of the nodule leading to infection
o fistulas (draining channels) that connect the inside of the nodule to the skin surface. Fistulas can easily become infected.
Surgical removal is an option. Patients with rheumatoid nodules tend to heal more slowly than people without the disease. As a result, removal of nodules needs to be done carefully and the surgical wound monitored carefully for dehiscence (reopening). In particular, patients who are taking corticosteroids may be the ones who need to be monitored most carefully. Nodules may also reoccur, particularly if they are located in areas where there is repetitive pressure or trauma.
Steroid injections into the nodule may reduce the size of the nodule.