@article{oai:nagasaki-u.repo.nii.ac.jp:00001614,
 author = {Endo, Yushiro and Fujikawa, Keita and Koga, Tomohiro and Mizokami, Akinari and Mine, Masanobu and Tsukada, Toshiaki and Uetani, Masataka and Kawakami, Atsushi},
 issue = {7},
 journal = {Medicine},
 month = {Feb},
 note = {Spondyloarthritis may be increasingly present in older patients as life expectancy increases. We investigated clinical differences between early-onset and late-onset spondyloarthritis in Japan.
We retrospectively reviewed 114 patients consecutively diagnosed with spondyloarthritis. The clinical course of each patient was observed for ?1 year. We defined early-onset and late-onset spondyloarthritis as <57 or ?57 years at a median age of this study group,respectively. 
We compared clinical characteristics between these 2 groups.Disease duration was significantly shorter before diagnosis in the late-onset group (P?<?.01). Inflammatory back pain (IBP) was significantly more common in the early-onset group (P?<?.01), whereas dactylitis frequency was significantly higher in the late-onset group. Significantly more patients with early-onset spondyloarthritis were human leukocyte antigen (HLA) B27-positive (P?<?.01). Articular synovitis, 
particularly of the wrist, was significantly more common on power Doppler ultrasound (PDUS) in the late-onset group (P?<?.01). 
Tenosynovitis or peritendinitis, particularly in the finger and wrist flexors were also more frequent in the late-onset group (P?<?.001 and P?<?.05, respectively). 
Enthesitis of the finger collateral ligament and lateral collateral ligament were significantly more common in the late-onset group (both P?<?.05). Multiple logistic regression analysis revealed that, comparatively, IBP was significantly and independently much more likely to occur in the early-onset group.The patients with late-onset spondyloarthritis had a lower frequency of IBP and HLA B27 and a higher frequency of dactylitis and PDUS findings in peripheral involvement., Medicine, 98(7), e14431; 2019},
 title = {Characteristics of late-onset spondyloarthritis in Japan: A retrospective cohort study},
 volume = {98},
 year = {2019}
}