Clinical Manifestations and Diagnosis of Axial Spondyloarthritis

Abstract

Background: Axial spondyloarthritis (axSpA) is a chronic, rheumatic disease characterized by inflammation of the sacroiliac joint, spine, and entheses. Axial spondyloarthritis affects up to 1.4% of adults in the United States and is associated with decreased quality of life, increased mortality, and substantial health care-related costs, imposing a high burden on patients, their caregivers, and society.

Summary of work: Diagnosing axSpA can be difficult. In this review, we seek to help rheumatologists in recognizing and diagnosing axSpA.

Major conclusions: A discussion of challenges associated with diagnosis is presented, including use and interpretation of imaging, reasons for diagnostic delays, differences in disease presentation by sex, and differential diagnoses of axSpA.

Future research directions: The early diagnosis of axSpA and advances in available therapeutic options have improved patient care and disease management, but delays in diagnosis and treatment remain common. Additional research and education are critical for recognizing diverse axSpA presentations and optimizing management early in the course of disease.

FIGURE 1

The 5 parameters that independently contribute to inflammatory back pain based on the ASAS criteria; inflammatory back pain requiring further investigation is usually indicated if 4 or more parameters are positive.

FIGURE 2

A summary of the (A) 2009 ASAS classification criteria for axSpA in patients presenting with chronic back pain lasting 3 months or more and age at onset of younger than 45 years^, and (B) 1984 modified New York criteria for AS. The ASAS criteria account for patients with and without radiographic sacroiliitis. Furthermore, patients meeting both the ASAS and modified New York criteria are classified as having AS.^,

FIGURE 3

A diagnostic guide for axSpA among patients with chronic low back pain lasting 3 months or more and age at onset of younger than 45 years. A, Spondyloarthritis features include alternating buttock pain, dactylitis, asymmetrical arthritis, elevated acute-phase reactants (e.g., CRP or erythrocyte sedimentation rate), enthesitis, inflammatory back pain, inflammatory bowel disease, family history of SpA in a first- or second-degree relative, marked response to NSAIDs, psoriasis, and uveitis. B, The figure was modified from its original version to suggest that MRI of the sacroiliac joints may be appropriate in some patients who are x-ray– and HLA-B27–negative but who have 2 to 3 SpA features.