The more common symptoms of juvenile spondyloarthritis include arthritic pain, especially around the heels or toes, around the knee, and in the lower back. Frequently, the first symptom is pain at the site where ligaments and tendons attach to bone (the inflammation at this location is called enthesitis). Months or years later, other joints may be affected, particularly joints of the spine or sacroiliac (SI) joints – the joints at the base of the spine, where the spine meets the pelvis.
At the beginning of the disease, children often have inflamed, swollen joints like the knees and ankles, but in adults, the spine is more likely to be involved. This inflammation can cause permanent damage if left untreated.