Classification Criteria for Axial Spondyloarthritis

In patients with spondyloarthritis (SpA), an early diagnosis is becoming more relevant as early effective treatment affects long-term outcomes. Several therapies have been shown to be efficacious to control disease symptoms and signs, and they are more efficacious if administered in early stages of the disease. However, the aim of an early diagnosis is not easy to achieve. Similar to the majority of rheumatic diseases, the diseases included under SpA differ in their presentations and natural course and lack a clinical, laboratory, or imaging biomarker beyond sacroiliitis to serve as a “gold standard” for diagnosis. With new treatment modalities becoming available, development of classification criteria has been an important focus of research in this field during the past decades.