Spondyloarthritis in a pediatric population: risk factors for sacroiliitis.
OBJECTIVE
Pediatric rheumatologists may have an opportunity to diagnose sacroiliitis in its early stages, prior to the development of irreversible radiographic changes. Early diagnosis frequently requires magnetic resonance imaging (MRI), the use of which is limited by expense and requirement for sedation. We set out to identify features of juvenile spondyloarthritis (SpA) associated with the highest risk of sacroiliitis, to identify patients who may be candidates for routine MRI-based screening.


METHODS
We reviewed the charts of 143 children seen at Texas Scottish Rite Hospital for Children diagnosed with SpA based on the International League of Associations for Rheumatology criteria for enthesitis-related arthritis or the Amor criteria for SpA. We performed logistic regression analysis to identify risk factors for sacroiliitis.


RESULTS
A group of 143 children were diagnosed with SpA. Consistent with the diagnosis of SpA, 16% had psoriasis, 43% had enthesitis, 9.8% had acute anterior uveitis, and 70% were HLA-B27+. Fifty-three children had sacroiliitis, of which 11 cases were identified by imaging studies in the absence of suggestive symptoms or physical examination findings. Logistic regression analysis revealed that hip arthritis was a positive predictor of sacroiliitis, while dactylitis was a negative predictor.


CONCLUSIONS
Children with SpA are at risk for sacroiliitis, which may be present in the absence of suggestive symptoms or physical examination findings. The major risk factor for sacroiliitis is hip arthritis, while dactylitis may be protective. Routine screening by MRI should be considered in patients at high risk of developing sacroiliitis.
Stoll
Matthew L
ML
Department of Pediatrics, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9063, USA. Matthew.Stoll@UTSouthwestern.edu
Bhore
Rafia
R
Dempsey-Robertson
Molly
M
Punaro
Marilynn
M
D002648:Child; D015796:HLA-B27 Antigen / Q000276:immunology; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D016017:Odds Ratio; D012307:Risk Factors; D058566:Sacroiliitis / Q000150:complications* / Q000276:immunology; D012680:Sensitivity and Specificity; D025241:Spondylarthritis / Q000150:complications* / Q000276:immunology; D013781:Texas
D015796:HLA-B27 Antigen