Ankylosing Spondylitis with Subcutaneous Nodules

IS ankylosing spondylitis a distinct entity1 2 3 4 5 6 7 8 9 10 or a variant of rheumatoid arthritis?11 12 13 14 15 16 17 McEwen et al.18 regard spondylitis restricted to sacroiliac joints and spine, with or without hip and shoulder involvement, as a distinct disorder; spondylitis with peripheral joint disease is considered a variant of rheumatoid arthritis. There seem to be sufficient differences between the two conditions clinically, radiologically, serologically and therapeutically to justify Graham's7 conclusion that ". . . The enforced marriage of rheumatoid arthritis and ankylosing spondylitis should be annulled on the basis of incompatibility."A striking difference between ankylosing spondylitis and rheumatoid arthritis cited by proponents of the . . .