Atypical spondyloarthritis in children: proposed diagnostic criteria.

Clinical and laboratory findings in 26 children with atypical spondyloarthritis were compared with those of 76 children with juvenile rheumatoid arthritis. The sensitivity, specificity, predictive value, and efficiency for diagnosis were calculated. The following findings (major criteria) were much more common in atypical spondyloarthritis than in juvenile rheumatoid arthritis: (1) spondyloarthritis within the family; (2) enthesopathy; (3) arthritis of digital joints; (4) sacro-iliitis; (5) presence of HLA-B27; (6) frequent recurrence of arthritis and arthralgia. Six additional findings (minor criteria) were significantly more common in atypical spondyloarthritis (SA): (1) disease onset after the age of 10 years; (2) male sex; (3) involvement of the lower extremities; (4) acute iridocyclitis or conjunctivitis; (5) arthritis of the hip joints; (6) manifestation following a history of enteritis. In the presence of 4 major criteria or 3 major and 3 minor criteria, the diagnosis of an atypical SA was established with a sensitivity of 84.6%, a specificity of 100%, and an efficiency of 96.1%.