Update on juvenile spondyloarthritis

Abstract

Spondyloarthritis (SpA) encompasses a group of disorders linked by overlapping clinical manifestations and genetic predisposition. Newer classification systems developed for adults with SpA focus on identifying individuals with axial or predominantly peripheral involvement. All forms of SpA can begin during childhood, and can be considered on a continuum with adult disease. Nevertheless, there are important differences in presentation and outcome that depend on age at onset. This article highlights these differences, what has been learned about genetics and pathogenesis of SpA, and important unmet needs for future studies.

Keywords: Axial spondyloarthritis; Enthesitis-related arthritis; HLA-B27; Juvenile psoriatic arthritis; Juvenile spondyloarthritis.

Figure 1

Achilles tendon enthesitis. Heels of a nineteen year old HLA-B27-positive male with enthesitis and peripheral arthritis. Area of right Achilles tendon insertion on calcaneus is swollen, slightly erythematous, and tender to palpation, despite ongoing treatment with a TNF inhibitor.

Figure 2

Whole body MRI in suspected early AS. Twenty-eight year old HLA-B27-positive male with inflammatory back pain for 7 months was evaluated. STIR images show (left) bone marrow edema adjacent to the lower portions of SI joints (open arrows), and (right) in anterior corners (closed arrows) of thoracic vertebral bodies. Image reproduced from reference with permission from author.

Figure 3

Whole body MRI of sixteen-year old HLA-B27-positive male with a one-year history of knee and hip pain, and six months of inflammatory back pain. Patient was on indomethacin at the time of imaging. STIR images of (A) thoracic region showing enhanced signal at cost over tebral junction (arrow), and (B) pelvis showing bone marrow edema on both the iliac and sacral sides of the sacroiliac joints bilaterally.

Figure 4

Radiographic images of sacroiliac joints of 19-year old HLA-B27-positive male with two-year history of intermittent lower back pain and one episode of acute anterior uveitis. Plain radiographs (A, B) and CT scan (C) of sacroiliac joints. (A, B) reveal minimal sclerosis bilaterally with joint space widening (grade II). (C)Erosions and sclerosis.

Figure 5

STIR image from whole body MRI of 19-year old male with two-year history of intermittent hip and alternating buttock pain, but lacking inflammatory back pain. Bone marrow edema is apparent on sacral and iliac sides of left sacroiliac joint. Patient had previous MRI showing bone marrow edema adjacent to the right sacroiliac joint correlating with right-sided symptoms.