Recent Updates in Juvenile Spondyloarthritis

Abstract

Spondyloarthritis represents a group of disorders characterized by enthesitis and axial skeletal involvement. Juvenile spondyloarthritis begins before age 16. Joint involvement is usually asymmetric. Bone marrow edema on noncontrast MRI of the sacroiliac joints can facilitate diagnosis. The most significant risk factor for axial disease is HLA-B27. Most patients have active disease into adulthood. Enthesitis and sacroiliitis correlate with greater pain intensity and poor quality-of-life measures. Tumor necrosis factor inhibitors are the mainstay of biologic therapy. Although other biologics such as IL-17 blockers have shown benefit in adult spondyloarthritis, none are approved by the US Food and Drug Administration.

Keywords: Enthesitis-related arthritis; Juvenile idiopathic arthritis; Juvenile psoriatic arthritis; Pediatrics; Spondyloarthritis.

Figure 1.

Dactylitis of the 2^nd toe on the right foot in a child with juvenile psoriatic arthritis. Courtesy of Dr. Carlos Rose.

Figure 2.

Nail pitting in a 9-year old female with juvenile psoriatic arthritis.

Figure 3.

X-ray of SI joints from a 20-year old male who had disease onset at 14 years of age. X-ray shows bilateral erosion and subchondral sclerosis that is more prominent on the right.

Figure 4.

Coronal oblique STIR image of the SI joints in an 18-year old HLA-B27 positive male demonstrating bilateral sacroiliitis. Bone marrow edema on the iliac and sacral side of the right SI joint is indicative of active sacroiliitis. The left SI joint shows chronic appearing changes, including prominent erosive changes and milder bone marrow edema of the iliac and sacral sides of SI joint (long white arrow).

Figure 5

5A and 5B. Coronal oblique STIR (5A) and T1 weighted (5B) images of SI joints from an 11-year old normal female child. Notice the areas of homogeneous bilateral symmetric rims of subchondral STIR hyperintensity within subarticular bone of the sacrum (white arrows).

Figure 6.

STIR image from whole body MRI of a 15-year old male with HLA-B27 positive JSpA depicting sacroiliac and hip joints. There is subchondral bone marrow edema and a focal erosion within the right iliac bone adjacent to inferior aspect of the right SI joint (long white arrow). Also note bone marrow edema of the greater trochanters bilaterally (short white arrows), reflecting enthesitis.

Figure 7.

STIR image from whole body MRI of a 15-year old male with HLA-B27 negative JSpA. MRI shows active corner inflammatory lesions of vertebral end plates at multiple levels (straight white arrows), and more chronic appearing disco-vertebral unit changes (curved white arrow).