Ankylosing spondylitis (AS) is recognized as the primary condition within a group of related diseases known as spondyloarthropathies. This broader category includes reactive arthritis, psoriatic arthritis, arthritis linked to inflammatory bowel diseases (enteropathic arthritis), and undifferentiated spondyloarthropathies. While ankylosing spondylitis and spondyloarthropathies are commonly diagnosed in younger individuals, they can also manifest later in life, affecting individuals over the age of 50. In fact, all subgroups of spondyloarthropathy can be observed in the elderly, sometimes presenting with unique characteristics specific to this age demographic.
One of the key challenges in diagnosing ankylosing spondylitis after 50 lies in the interpretation of radiological findings. Age-related changes in the body can complicate radiographic assessments, making it harder to distinguish between changes due to aging and those indicative of ankylosing spondylitis. This necessitates a careful and nuanced approach to diagnosis in older patients.
Late-onset peripheral spondyloarthropathies often present as a severe form of the disease. These cases are marked by significant elevations in laboratory markers of inflammation, oligoarthritis primarily affecting the lower limbs, and the presence of oedema in the extremities. Psoriatic arthritis also tends to exhibit a more aggressive course in elderly patients and is often associated with poorer outcomes compared to younger individuals diagnosed with the same condition. Undifferentiated spondylarthropathy in the elderly can manifest with the same diverse range of clinical presentations as seen in younger and middle-aged adults, making diagnosis potentially complex due to the overlap with other age-related ailments. Reactive arthritis and enteropathic arthritis, while less frequently observed in older populations, still occur and should be considered in differential diagnoses.
Managing late-onset ankylosing spondylitis and spondyloarthropathies in older adults presents therapeutic challenges. The effects of aging on drug metabolism and pharmacokinetics, coupled with the increased likelihood of co-existing health conditions (co-morbidities) and the use of multiple medications (polypharmacy), complicate treatment strategies. Non-steroidal anti-inflammatory drugs (NSAIDs), commonly used to manage inflammation and pain in AS, should be administered cautiously in older patients due to the elevated risk of serious gastrointestinal complications. Disease-modifying antirheumatic drugs (DMARDs) like sulfasalazine and methotrexate have been utilized, but their effectiveness in late-onset AS has been limited.
Alternative therapeutic options such as pamidronate and tumor necrosis factor (TNF)-alpha antagonists offer potential benefits. Pamidronate has shown promise in younger patients with ankylosing spondylitis and spondyloarthropathies, although results have varied. Importantly, it appears to be safe for use in older patients without significant adverse effects. TNF-alpha antagonists have been well-studied and demonstrated significant improvements in clinical and biological measures of disease activity in ankylosing spondylitis and spondyloarthropathies. However, the safety profile of these powerful agents in elderly individuals is not yet fully established. Therefore, when using TNF-alpha antagonists in older patients, careful monitoring is crucial, particularly for the risk of infections such as tuberculosis, and the potential exacerbation of chronic heart failure.
In conclusion, diagnosing ankylosing spondylitis after the age of 50 requires careful consideration of age-related factors and potential diagnostic challenges. While late-onset AS can present with unique characteristics and therapeutic complexities, awareness and careful management strategies can help improve outcomes for older adults living with this condition.
