Juvenile spondyloartropathies.

Juvenile spondyloarthropathies (JSpA) are defined as a heterogeneous group of diseases that start before the age of 16, which is associated with peripheral joint (especially large joints of the lower limbs) and axial skeletal (spine and sacroiliac joint) involvement, enthesitis, and human leukocyte antigen (HLA) B27 positivity. Juvenile spondyloarthropathies mainly cover juvenile ankylosing spondylitis (JAS), psoriatic arthritis, reactive arthritis, inflammatory bowel disease-associated arthritis, seronegative enthesopathy, arthropathy syndrome (SEA), and enthesitis-associated arthritis. Symptoms associated with spondyloarthropathies are enthesitis, inflammatory low back pain, dactylitis, nail changes, psoriasis, acute anterior uveitis, and inflammatory bowel disease-related symptoms. In JSpA, axial involvement is rarely seen in the early stages of the disease, in contrast to adult patients with ankylosing spondylitis (AS). The disease usually begins as asymmetric oligoarthritis of lower extremities in children, and axial skeletal involvement can occur in the course of the disease. Although the debate on the classification of juvenile spondyloarthropathies continues due to its initial nonspecific findings and the heterogeneity of the disease phenotype, the International League of Associations Rheumatology (ILAR) classification criteria are the most commonly used pediatric criteria. In that set of criteria, patients with JSpA are mainly classified under enthesitis-related arthritis or psoriatic arthritis group. Since juvenile spondyloarthropathies can cause severe loss of function and long-term sequelae, the main goal in treatment should be suppression of inflammation as early as possible and prevent sequelae.