Rheumatoid arthritis in the elderly.

What is currently classified as rheumatoid arthritis in the elderly (that is, late onset after age 60) may in fact include a number of separable distinct diseases. Identifiable subsets include seropositive or 'classic' rheumatoid arthritis, Sjögren's syndrome with a limited form of arthritis, and a seronegative benign synovitis akin to polymyalgia rheumatica.