Enthesis related juvenile idiopathic arthritis

enthesitis realted juvenile idiopathic arthritis

Enthesitis related arthritis (ERA) is a condition which mainly affects male patients after the age of 6 years and is characterized by the association of enthesitis and arthritis (1,2,3):

• both JIA and juvenile spondyloarthropathie features are seen in these patients
• several names were used to describe ERA - e.g. - type 2 oligoarticular JIA, juvenile chronic arthritis (JCA) with late onset, seronegative enthesopathy and arthropathy, arthropathy associated with HLA B27 or juvenile spondyloarthropathy with early onset

In patients with ERA:

• RF and ANA are negative
• HLA B27 positivity is reported in 65-80 %
  • HLA-B27 positivity is associated with more severe disease, sacroiliitis, juvenile ankylosing spondylitis, and acute anterior uveitis (4)
• enthesopathy and asymmetric arthritis of the lower extremities are characteristic features
  • enthesopathy
    • presence of inflammation of the attachment sites of the tendons to the bones defines enthesitis-related arthritis (1,2,3,4)
    • the peripatellar and calcaneal entheses are most frequently affected (4)
      • patellar insertion of the quadriceps tendon
      • calcaneal and metatarsal insertions of the plantar fascia
    • there is pain and sensitivity at the affected site
  • arthritis
    • asymmetric oligoarticular lower-extremity arthritis are seen typically
    • knee and ankle are affected commonly
    • arthritis could progress to affect the sacroiliac and spinal joint
    • enthesitis and synovitis of peripheral joints (e.g., upper and lower extremities) often coexist (4)
    • symptomatic axial involvement (e.g., sacroiliitis, inflammatory spine disease, or both) develops in 40 to 60% of patients with enthesitis-related arthritis, usually during adolescence (4)
• primary extra articular manifestation in acute anterior uveitis

Reference:

• (1) Barut K, Adrovic A, Şahin S, Kasapçopur Ö. Juvenile Idiopathic Arthritis. Balkan Medical Journal. 2017;34(2):90-101.
• (2)Weinstein SL, Flynn JM. (2013). Juvenile Idiopathic Arthritis. Lovell and Winter’s Pediatric Orthopaedics (7th ed., pp. 348-368)
• (3) Makay B, Unsal E, KasapcopurO. Juvenile idiopathic arthritis. World J Rheumatol. 2013; 3(3): 16-24
• (4) Sandborg CI et al. Juvenile Idiopathic Arthritis. NEJM 2025;393:162-174.