Inflammatory Polyarthritis in the Older Adult
Rheumatoid arthritis is the most common etiology for inflammatory arthritis in the older population, with an estimated prevalence of 2%. An older individual with inflammatory polyarthritis usually falls into one of two categories. The first consists of patients with well-established long-standing disease, whose course is often confounded by end organ damage and toxicity related to antirheumatic drugs. The other category comprises patients with late-onset inflammatory polyarthritis, whose presentation is often nonspecific and, thus, more elusive to diagnose. Systemic lupus erythematous can also occur in the older adult; it is less prevalent than rheumatoid arthritis and is associated with multiple organ involvement, including musculoskeletal symptoms.
Key words: rheumatoid arthritis, systemic lupus erythematosus, inflammatory polyarthritis, late-onset disease.
Introduction
According to the 2000 Canadian Community Health Survey, at least four million Canadians 15 years and older are afflicted with a musculoskeletal (MSK) condition.1 Forty percent of these individuals are over the age of 65 years. Compared with people with other chronic conditions, those with arthritis experienced more pain, activity restrictions, and long-term disability. They more frequently reported contact with health care professionals in the previous year.2
Although noninflammatory arthritis, such as osteoarthritis (Figure 1), is the predominant etiology behind these MSK symptoms, inflammatory arthritis can also occur within this population. As inflammatory polyarthritis results in greater frequency of constitutional symptoms, joint swelling, and damage than osteoarthritis, identification and timely management of these inflammatory conditions is of paramount importance. Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) account for a significant proportion of symmetrical inflammatory polyarthritis seen in older adults.
An older individual with inflammatory polyarthritis usually falls into one of two categories: a patient with well-established long-standing disease or a patient with a new late-onset inflammatory polyarthritis. The first group is usually characterized by patients with a high burden of damaged joints and possible clinical manifestations of treatment toxicity as a result of long disease duration. They may or may not have smouldering disease activity during their later years. Management options for persons with long-standing disease are usually more restricted due to a prior history of primary or secondary failure to traditional therapeutic modalities.
Patients with late-onset inflammatory polyarthritis are often challenging to diagnose, as the symptoms are more likely to be nonspecific and exhibit a different pattern of synovitis than those classically described for early onset polyarthritis. For instance, older RA patients are more likely to present with systemic complaints such as generalized weakness, anorexia, weight loss, fatigue, or fever, and onset of joint symptoms typically is abrupt. An additional challenge with late-onset disease is the prevalence of concomitant disease that may also mask inflammatory disease such as polymyalgia rheumatica, malignancy, and even osteoarthritis. In this review, we discuss the clinical presentation and treatment of RA and SLE, and highlight additional issues germane to treating older patients.
Rheumatoid Arthritis
Epidemiology
RA is the most common inflammatory arthritis, with an estimated overall prevalence of 1%, which increases to at least 2% in the older population.3 Females with young-onset RA (RA onset prior to the age of 60) are two to four times as likely to be affected as males. This ratio decreases to 1.5 to 1 for females in late-onset RA (RA onset after the age of 60).4
Diagnosis
Diagnosis of RA follows the 1987 American Rheumatism Association criteria. Criteria for RA diagnosis