Axial spondyloarthritis (axial SpA) is a chronic inflammatory disease that primarily affects the spine and sacroiliac joints, leading to significant pain and discomfort. The condition, however, remains underdiagnosed, especially in its non-radiographic form. At the 2024 Rheumatology Nurses Society annual conference, J. Nicholas Manwaring, MSN, APRN, emphasized the importance of understanding the fluid nature of axial SpA to prevent serious complications and ensure early intervention.

The Prevalence of Chronic Back Pain and Its Misdiagnosis

Chronic back pain is one of the most common issues seen in healthcare, affecting millions of people worldwide. For those with axial SpA, this pain often goes misdiagnosed or undiagnosed for years, leading to delayed treatment and worsening symptoms. Manwaring, a commander in the U.S. Public Health Service Commissioned Corps, highlighted how both radiographic and non-radiographic forms of axial SpA are often under-recognized. In fact, between 10% and 40% of patients with non-radiographic axial SpA eventually develop radiographic disease, indicating the importance of close follow-up.

“It is really underdiagnosed,” Manwaring noted. “It is important that we continue to follow up with these patients because these diagnoses are fluid, they are not static.”

The Fluidity of Axial SpA

Axial spondyloarthritis is not a one-size-fits-all condition. The disease can present with a range of symptoms that fluctuate over time. Patients may experience periods of remission, where symptoms are minimal, followed by flare-ups of inflammatory back pain and peripheral involvement, such as enthesitis (inflammation of tendons and ligaments), sacroiliitis (inflammation of the sacroiliac joint), or uveitis (eye inflammation).

Because of this variability, axial SpA can be challenging to diagnose, and its complexity requires a nuanced approach to patient care. Manwaring stressed that clinicians must not assume the disease will follow a straightforward progression. Some patients may never develop radiographic evidence of disease, while others may fall outside traditional diagnostic criteria altogether.

“Sometimes it goes into remission, and sometimes it develops into non-radiographic axial SpA,” Manwaring said, emphasizing the need for clinicians to remain vigilant, even in cases where early signs of the disease are unclear.

Genetic and Environmental Factors

The role of genetics in axial SpA is well-documented, with the HLA-B27 gene mutation being one of the most recognized markers for the disease. However, Manwaring cautioned against relying too heavily on genetic markers when diagnosing axial SpA. “Do not put all your money on HLA-B27,” he said, explaining that the presence of this mutation varies by ethnicity and background.

Environmental factors, combined with genetic predispositions, likely play a role in the development of axial SpA. Clinicians must consider a patient’s full medical history and environment when diagnosing the condition, as relying solely on genetic testing could result in missed or delayed diagnoses.

Optimizing Diagnostic Tools

Given the complexity of axial SpA, it’s important for clinicians to use optimized imaging strategies to aid in diagnosis. Manwaring recommends the AP pelvis X-ray as the best initial imaging method, with bilateral views of the sacroiliac joint providing additional clarity. The goal of early and accurate imaging is to catch the disease before it progresses and causes irreversible damage.

“The best X-ray for the initial view is the AP pelvis,” Manwaring stated. “Bilateral views of the sacroiliac joint are also helpful.”

Preventing Disease Progression

The ultimate objective in understanding the fluid nature of axial spondyloarthritis is to prevent disease progression before it leads to debilitating outcomes. Once the disease progresses to the point of complete effusion of the spine, treatment options become limited, and the patient’s quality of life suffers significantly.

By fostering a deeper understanding of the disease and employing vigilant diagnostic techniques, healthcare providers can catch axial SpA early and offer appropriate treatment to slow its progression. This approach not only prevents serious complications but also improves long-term patient outcomes.

Axial spondyloarthritis is a dynamic and complex disease that requires ongoing monitoring and individualized care. The fluid nature of the disease, along with its underdiagnosis, makes it essential for clinicians to remain proactive in identifying and treating axial SpA. Genetic markers such as HLA-B27 can provide some guidance, but they should not be the sole determinant in diagnosis. Early intervention, combined with optimized imaging and a nuanced understanding of the disease’s variability, can prevent the severe outcomes associated with untreated axial SpA.

The American Arthritis Foundation is committed to raising awareness about axial SpA and supporting patients in managing their condition. By understanding the fluidity of the disease and working closely with healthcare providers, patients can take control of their health and prevent the long-term consequences of this debilitating condition.