A rheumatoid nodule is one of the most common skin manifestations of rheumatoid arthritis. Rheumatoid arthritis is a chronic disease that causes inflammation of the joints and results in painful movement and stiffness, especially in the fingers, wrists, and ankles. Nodules are large, painful bumps that often develop in the joints of the fingers and also on the elbows, forearm, back, heel and many other areas.