Well, this is not going to be particularly helpful, since I don't have a specific cite or link, but I'm sure I've read at least one paper putting forth the idea that ALL the spondyloarthropathy's are a kind of reactive arthritis...that Reiter's is a simply AS with a subset of symptoms and not really an entity unto itself, or rather, AS is just a form of Reiter's.
The overlap to me has always seemed to point out the limitation of the clinical distinctions made among the SpAs, except in making guesses at how the disease will progress, which might apply to groups, though not a specific patient.
