Ankylosing spondylitis with subsequent development of rheumatoid arthritis, Sjögren's syndrome, and rheumatoid vasculitis.

Twelve years after the onset of ankylosing spondylitis, a patient developed severe seropositive rheumatoid arthritis with subcutaneous nodules. This was subsequently complicated by Sjögren's syndrome and rheumatoid vasculitis. The literature is reviewed, and the nature of the association between ankylosing spondylitis and rheumatoid arthritis is discussed.