Inflammatory bowel disease (IBD) (Johns Hopkins image), which includes Crohn’s disease and ulcerative colitis, is an autoimmune process involving inflammation of the gout, However, IBD frequently presents with symptoms outside of the GI tract. One of the more common symptoms can be arthritis, which occurs in approximately 10% – 20% of people with IBD. In fact, some patients even present with the arthritis before the diagnosis of IBD is recognized. The disease may begin at any age, but occurs most often in young adults, affecting males and females in equal distribution.
The pattern of the arthritis is variable, but it commonly affects the lower extremity joints, such as the knees and hips. Joint deformities are rare, and the arthritis tends to not cause erosive damage. In ulcerative colitis, the activity of the arthritis often parallels the activity of the bowel inflammation.
Arthritis related to IBD can also affect the axial skeleton, or spine. This arthritis, called spondyloarthropathy (Image) occurs more in men than in women and most commonly affects the lower spine, such as the lumbar spine and sacroiliac joints. However, the amount of spine inflammation does not correlate with the degree of bowel inflammation. There is also an association with the HLA-B27 gene, although much lower than with ankylosing spondylitis.
The pathogenesis of IBD and spondyloarthropathy suggests an interplay between genetic, environmental, and immunological factors. However, the exact cause is still an area of active research. There are multiple genetic factors that have been implicated, including an association with the HLA-B27 gene. However, this association is much lower than in patients with ankylosing spondylitis. Regarding environmental factors, there appears to be an association between bowel inflammation and changes in the gut bacteria, commonly referred to as the gut microbiome. This change in the gut microbiome is important and an area of ongoing and active research.
Other manifestations of IBD outside of the GI tract, in addition to arthritis, include skin lesions, certain types of eye inflammation, vasculitis, and osteoporosis.
The treatment of the arthritis associated with IBD involves treatment of the underlying bowel disease. However, sometimes there can be active joint inflammation despite good control of the GI inflammation, so the management requires a multidisciplinary approach between the gastroenterologist and rheumatologist. Often, strong immunosuppressive medications called biologics are needed to suppress both the gut inflammation as well as the arthritis and other extraintestinal manifestations.