Pediatric Rheumatology Online Journal → June 2003 → Enthesitis-related arthritis and Psoriatic arthritis→ Abstract #20

ENTHESITIS RELATED ARTHRITIS: CLINICAL, LABORATORY AND RADIOGRAPHIC FEATURES AT PRESENTATION IN A LARGE SINGLE INSTITUTION COHORT

C. M. A. Leblanc,¹ B. M. Feldman,² R. M. Laxer.²

¹Pediatrics, Children;s Hospital of Eastern Ontario, Ottawa, ON, Canada; ²Pediatrics, Division of Rheumatology, Hospital for Sick Children, University of Toronto, Toronto, ON, Canada

Background
Enthesitis related arthritis(ERA) is a common subgroup of JIA, which may lead to ankylosing spondylitis(AS). No large ERA studies exist.
Objective
To document early clinical, laboratory and radiographic features in ERA.
Methods
Retrospective cohort of ERA patients @ Hospital for Sick Children rheumatology clinic was evaluated as part of long-term functional outcome study. Follow-up 5 years excluded. Clinical, laboratory and radiographic features documented at presentation. Pauci or polyarticular disease established at baseline and 6 months. Management recorded.
Results
84 ERA charts reviewed. Initial diagnoses: undifferentiated spondyloarthopathy(31%), SEA(23%), Reiter;s/ReA(18%), type II JRA(17%), JAS(7%), other arthritis(2%). No IBD patients met ERA criteria. Average age 12 +/- 2.5 years. F:M = 11/73. Family history spondyloarthritis in 18%(AS 16%). Mean joint count 3.7 at presentation(62% lower limbs); at six months 3.2(56% lower limbs). Hip arthritis(30%) and tarsitis(13%) were common. 4/21 patients had abnormal hip X-Rays. 13% had SI pain; X-Rays in 13/29(45%) showed sacroillitis.17% patients had back pain, 10% L/S movement but 0/6 had spinal X-Ray changes. Lower limb enthesitis prevalent (tibial tuberosity 17%, Achilles 18% and 23% plantar);15% of patients had dactylitis. Extra-articular involvement: GI(35%), acute uveitis(18%), urethritis(12%). Positive HLA B27(61/78); negative ANA(63/80) and RF(74/75). High mean IgA 2.2 +/- 0.98 G/L. Poor response to NSAIDs(23%) and IAS(8.3%) was seen;36% patients received Sulfasalazine, 19% needed oral steroids and 10% took other agents.
Conclusion
This is the largest cohort of patients with ERA reported to date and confirms most patients are seronegative, HLA B27 positive males 10 years old with pauciarticular disease. Hip pain is common. Early onset back arthritis is uncommon. Radiographic SI changes are frequent even in asymptomatic patients. Dactylitis and extraarticular features are common. Many have poor response to NSAIDs.