Spondyloarthropathy identified as the etiology of Nubian erosive arthritis.

Slight variation in manifestation of different diseases may allow a single individual with one disease to mimic the "classic" appearance of another, as evidenced by the frequent confusion of spondyloarthropathy with rheumatoid arthritis. Analysis of population occurrence of arthritis (rather than isolated skeletons) facilitates more precise diagnosis. Northeast Africans living around 2,000 years before present were clearly afflicted with a form of spondyloarthropathy. Lack of inclusion of spondyloarthropathy in the differential diagnosis of erosive arthritis led to past misclassification of Nubians as having rheumatoid arthritis. While evidence of spondyloarthropathy abounds in the literature of human skeletal disease, pre-Columbian Old World rheumatoid arthritis is still elusive. The current study further documents the absence of rheumatoid arthritis in Nubians, supporting the hypothesis that rheumatoid arthritis began in the New World.